Sonic the Hedgehog


 * This is about the version of the character in the game continuity. For other uses, see Sonic the Hedgehog (disambiguation).

"What you see is what you get! Just a guy who loves adventure. I'm Sonic the Hedgehog!"

- Sonic the Hedgehog

Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ) is the eponymous and main protagonist of the Sonic the Hedgehog series and Sega's mascot. He is a 15-year-old, blue, anthropomorphic hedgehog, and is a laid-back and cool-headed character, meant to symbolize peace. Like his name and species would imply, Sonic can move at the speed of sound (and can exceed this), with lightning fast reflexes to match it, and can as well curl up into a ball, primarily to attack enemies. These are the distinguishing traits that were used to make his character and world-famous video games.

Ever since stepping into the battle against injustice, Sonic has been the champion of peace. Well-known for his legendary cocky attitude, easy-going demeanor and somewhat short temper, yet strong sense of justice and love for freedom and adventure, Sonic uses his abilities to protect the innocent and his world (as well as many others) from the forces of evil, especially his arch-enemy Doctor Ivo "Eggman" Robotnik who constantly seeks world domination.

Sonic has been acknowledged as the most recognizable and famous character in the Sonic the Hedgehog franchise according to an official popularity poll in 2011.

Concept and Creation
While several people have been involved in the creation of Sonic, the artist Naoto Ōshima, programmer Yuji Naka and designer Hirokazu Yasuhara are generally credited with the creation of the character.

In April 1990, SEGA requested a game capable of selling more than 1,000,000 copies; a character who could compete against Nintendo's Super Mario, and a character to replace Alex Kidd as the company's mascot. Several character designs were submitted by its AM8 research and development department. These included an armadillo (who was later developed into Mighty the Armadillo), a dog, a Theodore Roosevelt look-alike in pajamas (who was later used as the basis of the design of the main antagonist Doctor Eggman) and a rabbit (who would use its extendable ears to collect objects, an idea that was later used for Ristar). Eventually, the mascot they selected was Naoto Ōshima's submission, a spiky teal hedgehog codenamed "Mr. Needlemouse", later renamed Sonic. Sonic's color was based on the SEGA logo, his shoe buckles based on Michael Jackson, his shoe color based on Santa Claus, and his personality was inspired by future-President Bill Clinton's "get it done" attitude, who Ōhshima felt embodied a modern sensibility of wanting to get things done right away, righting wrongs as they presented themselves instead of letting them linger. Sonic was created without the ability to swim because of a mistaken assumption by Yuji Naka that all hedgehogs could not do so.

A group of fifteen started working on Sonic the Hedgehog and renamed themselves Sonic Team. The game's soundtrack was composed by Masato Nakamura of the band Dreams Come True. Sega sponsored the group's "Wonder 3" tour, painting Sonic on the tour bus, distributing pamphlets advertising the game, and having footage of the game broadcast above stage prior to its release.

The original concepts gave Sonic fangs and put him in a band with a human girlfriend named Madonna. However, a team from Sega of America, led by Madeline Schroeder, "softened" the character up for an American audience by removing these elements. This sparked a heated issue with Sonic Team. Naka later admitted that it was probably for the best. Sonic's precise age, weight, height and other physical characteristics vary depending on the continuity in which he appears and the style in which he is drawn. In the video games, Sonic's original design by Naoto Ōshima was with short spikes, a round body, one spike in his back and no visible irises. Artwork featuring this design and drawn by Akira Watanabe was displayed on the package artwork for Sonic the Hedgehog (1991), and most subsequent Sonic video games featured similar designs. When Sonic the Hedgehog 2 for the Mega Drive appeared, Sonic's proportions changed. The original 1:2 head to height ratio changed to 1:2.5.

Beginning with Sonic Adventure in 1998, Sonic was redesigned by Yuji Uekawa as a 15-year-old character, with longer legs and a less spherical body, longer and more drooping spikes, two spikes in his back, and emerald-green-colored eyes. Further subtle changes to the character's design have been made in subsequent games. Spin-off media such as comics and cartoons have featured variations on all these video game designs, with restrictions set by the standardized model sheets.

Early Life
Not much is known about Sonic's early life. It is unknown who his family is or if he has one, neither is it known how Sonic gained his trademark speed or if he was born with it. All that is known is that Sonic was born on Christmas Island, and that he has spent his life traveling the world while searching for adventure.

At some point in his life Sonic met Dr. Ivo Robotnik and they became enemies under unknown circumstances; though it could very possibly be the fact that Robotnik is always looking to get more power and to be ruler of any land he finds and knowing Sonic, he always chooses to help those in need. Since meeting with each other, Sonic fought Dr. Robotnik in an untold number of confrontations as the mad scientist attempted time and time again to conquer the world, with Sonic each time emerging victorious. Despite their many battles however, Sonic did not really account of his adversary.

Sonic the Hedgehog (1991)
Sonic's first recorded battle against his nemesis, Doctor Robotnik, was in the 1991 platform game Sonic the Hedgehog for the Sega Mega Drive/Genesis. In this game, Sonic heard news about Robotnik invading South Island after he had discovered that powerful relics, called the "Chaos Emeralds", were hidden on the island and so he sought them to use their power to produce weapons of mass destruction. Annoyed by Robotnik's perseverance, Sonic hurried to South Island to stop him. Once Sonic arrived, he was met by Robotnik who revealed his new method to enslave the animal residents: by trapping them inside robotic shells, he could turn them into Badniks that would then follow his every command, a method that left Sonic greatly shocked.

Despite having the whole island as his enemy, Sonic resolved to save the animals and get the Chaos Emeralds before Dr. Robotnik could get his hands on them. After traveling across the island while freeing the animal residents and gathering the Chaos Emeralds, Sonic entered the doctor's stronghold on the island, defeated the mad scientist, and managed to drive him off the island. With Robotnik defeated, Sonic reunited with his friends in Green Hill, where he released the Chaos Emeralds, with their power ensured the island's prosperity. After this adventure, Sonic became a well-known hero throughout the world.

Sonic the Hedgehog 2
In the 1992 sequel Sonic the Hedgehog 2 for the Sega Mega Drive, Sonic first performed his signature Spin Dash move. He also meets Miles "Tails" Prower for the first time.

Sometime prior to the events of the game, Sonic was traveling the world in his old airplane, the Tornado, in search of adventure. While steering his plane through the sky, Sonic discovered West Side Island and decided to land there. With nothing else to do, Sonic chose to relax and explore this new region. After a few days of exploring however, Sonic began to notice someone was following him. He saw that it was a young two-tailed fox called Tails, who had seen how fast Sonic could run and had come to idolize him. At first, Sonic was not particularly interested in the fox and left him alone. The young Tails continued to follow Sonic however, and Sonic came to be impressed by the young fox's determination and ability to keep up with him. As such, Sonic decided to let Tails hang around for the time being, despite still not paying any particular attention to him.

At the beginning of the game, Sonic was taking a nap under the Tornado, but he suddenly awakens to find something attacking West Side Island, tearing the place apart. Standing besides Tails during the initial attack, Sonic was enraged by the destruction befalling the island and believed that Dr. Robotnik was behind this, before running into the center of the attack to find the mad doctor.

It turned out that it was indeed Robotnik who was at his old schemes again. This time, he turned the animal residents of West Side Island into his Badnik army to find the Chaos Emeralds, which were located on the island, to create his ultimate weapon, the Death Egg, so that he could conquer the world. Accepting the challenge, Sonic headed off to stop Robotnik, get the Chaos Emeralds first, and save the island, with Tails following him all the way.

When Sonic obtained all seven the Chaos Emeralds, he discovered that their powers could turn him into Super Sonic. Tails was at his side in most of the adventure and proved to be great assistance to him, such as piloting the Tornado for Sonic. All the while, Sonic began to form a strong bond with Tails.

After freeing West Side Island, Sonic and Tails followed Robotnik into the sky onboard the Tornado, which had been repaired by Tails. With Tails piloting his airplane, Sonic managed to arrive in the Wing Fortress Zone. As soon as he stepped onboard, however, Sonic was forced to leave Tails behind, as Tails and the Tornado were shot down. Making his way through the massive fleet, Sonic found Dr. Robotnik and fought off his attempts to defeat him, only to witness the doctor making his escape in his rocket ship. No sooner after that, however, Tails arrived in the Tornado, now equipped with a rocket engine. Riding on the enhanced Tornado, Sonic and Tails managed to give chase to Robotnik's rocket ship, and succeeded in catching up with him. As Robotnik's ship was about to depart into space, Sonic grabbed onto it in time and hitched a ride with it onboard the Death Egg.

When on the Death Egg, Sonic fought Robotnik's secret weapon, Mecha Sonic, followed by a gigantic robot in the image of the scientist himself. After a heated battle, Robotnik was defeated once again, and Sonic escaped the exploding Death Egg by jumping off into space.

As Sonic descended through the atmosphere, he was soon saved from his unfortunate fall by Tails, who caught him with the Tornado. At the end of this adventure, Sonic had not only come to respect Tails, but also see him as a true friend he could rely on, and the two of them became the best of friends.

Sonic the Hedgehog CD
Sonic was solo once again in Sonic the Hedgehog CD (1993) for the Sega CD. At the beginning of the game, Sonic was traveling to Never Lake to visit the Little Planet, a small satellite that was near Earth once a year, which he had decided to explore. When Sonic arrived, however, he saw that the entire planet had been transformed into a mechanical wasteland and chained to a nearby mountain, thus preventing it from leaving. After avoiding some falling mountain debris, created by the massive chain, Sonic noticed Dr. Robotnik's face carved into the mountain where the chain was embedded; he knew that his arch-nemesis was behind this and up to no good again. Sonic traveled to the Little Planet with the intention of liberating it from the mad scientist's control. As he arrived, Sonic learned he could undo Robotnik's work by using Little Planet's time passages to change the planet's past and by collecting the mystical Time Stones, Robotnik's reason for invading the planet.

Shortly after his arrival, Sonic met a female hedgehog named Amy Rose, Sonic's biggest fan and want-to-be girlfriend, who was on the planet in hopes of meeting him. Sonic however, was far from excited to meet her and found her overwhelming interest in him annoying. However, only moments after Sonic met her, as they arrived at Collision Chaos, she was captured by Metal Sonic, the newest creation of Dr. Robotnik, which was built to rival Sonic in every way and defeat him for good. As Metal Sonic successfully escaped with Amy, Sonic now had the task of saving Amy as well.

Using his unrivaled speed, Sonic managed to travel through time and ensure a good future for the Little Planet. As he neared the end of his adventure, Sonic encountered Metal Sonic and the doctor once again, and had a race with his robotic counterpart on the Stardust Speedway and was victorious. In the ensuing victory of Sonic's, Robotnik accidentally damaged Metal Sonic severely which left him out of the picture for the time being, and Sonic was able to save Amy from captivity.

Sonic went on and defeated the doctor in a final battle at Metallic Madness. With his defeat however, the doctor's bases began exploding and were literally crumbling away, but Sonic managed to escape them and the Little Planet with Amy safely. After "seeing" to Amy's safety, Sonic destroyed the chain holding the Little Planet and stood in awe as the Little Planet went on to show Sonic's face in a shower of light as a sign of thanks to him before seemingly warping away from Sonic's planet, leaving many new flowers growing around the area.

Robotnik, on the other hand, seemingly managed to sneak a Time Stone off the Little Planet, but Sonic spotted him and managed to put an end to his current schemes by using his Spin Dash to shoot a rock in the direction of his flying machine, causing it to explode. After that, Sonic went on his adventuring ways around the world.

Sonic Chaos
In Sonic Chaos (also known as Sonic & Tails in Japan) for the Game Gear and Master System, Sonic and Tails were facing the threat of Dr. Robotnik sinking South Island by improperly using the Chaos Emeralds. Sonic and Tails had to collect the Emeralds before the doctor could (including the red one he already had in his possession) and liberated the island of his control once more.

Sonic the Hedgehog 3
In Sonic the Hedgehog 3 and its expansion Sonic & Knuckles, both released in 1994 for the Sega Mega Drive/Genesis, Sonic meets Knuckles the Echidna for the first time, who would become one of his oldest rivals, as he sought to destroy the Death Egg once and for all.

The story starts with Sonic taking a nap on the beach, until he was awoken by Tails who had discovered a large reaction of Chaos Energy out on the sea. At the same time, Sonic found an ancient ring washed on shore, which made him recall a legend he had heard about a floating Island in the sky with a highly unique culture that was supported by a powerful stone. Now filled with excitement, Sonic decided it was time for another adventure, and headed out with Tails in the Tornado to check out the reaction at sea.

When Sonic and Tails arrived at the location of the Chaos Energy reaction, they found the legendary Angel Island, the same island Sonic had thought of beforehand. The duo soon noticed however that the island was kept at the ocean's surface and not flying in the sky where it belonged. To Sonic's surprise this was due to the impact of Death Egg's crash landing, which Sonic thought it was destroyed after his adventure in Sonic the Hedgehog 2, but had actually just crash landed on the floating island and now was being rebuilt. Not intending to let Dr. Robotnik salvage and rebuild the Death Egg so he could use it to conquer the world, Sonic headed out with Tails to stop Dr. Robotnik from relaunching the Death Egg.

As they neared the Island, Sonic used the Chaos Emeralds he had collected prior to the game to transform into his Super State and began exploring the island. Shortly after arriving however, Sonic was ambushed by Knuckles the Echidna, the guardian of the floating island and its treasure, the powerful Master Emerald. The echidna, who had been tricked by Dr. Robotnik into believing that Sonic had come to steal the Master Emerald, somehow managed to force the Chaos Emeralds out of Sonic, and he returned to his normal form. After the loss of the emeralds, Sonic could only witness as Knuckles quickly snatched them and escaped to hide them, leaving Sonic and Tails forced to search the island for the emeralds.

Despite this setback, Sonic and Tails headed out to to liberate the island from the control of Dr. Robotnik's robots and destroy the Death Egg for good. After a long struggle, Sonic and Tails made it to the doctor's Launch Base, despite Knuckles' many attempts to stop them, and boarded the Death Egg just as it took off. Here, Sonic and Tails fought and managed to defeat Robotnik, with their battle taking its toll on the Death Egg at a critical point, making it crash into the Lava Reef Zone.

Sonic & Knuckles
In Sonic & Knuckles, after escaping the doctor's vessel, Sonic landed safely with Tails' help in the Mushroom Hill. Annoyed that the Death Egg had survived yet another crash landing, Sonic knew it would not be long before the doctor tried to revive the Death Egg again and headed out with Tails once more to destroy it once and for all and discover Robotnik's fate, while keeping the doctor from using the Master Emerald as its power to relaunch the Death Egg again.

As the duo was about to make their way through Mushroom Hill however, Sonic and Tails spotted Knuckles passing through a hidden doorway. After making sure Knuckles was gone, Sonic and Tails took a look on the hidden doorway themselves and found a Giant Ring. After entering this ring, Sonic found himself with Tails at the Emerald Shrine in the Hidden Palace Zone where the Master Emerald rested. Here, Sonic discovered the Chaos Emeralds' connection to the Master Emerald by witnessing them turn into Super Emeralds after exposure to the Master Emerald. Sonic also learned that these empowered emeralds allowed him to become Hyper Sonic, an even stronger form of Super Sonic.

After a long struggle, the heroic duo reached the Hidden Palace Zone on their own, where Sonic and Knuckles fought against each other for the first of many times to come. After his defeat at his hands, Sonic and Tails followed the red echidna as he went to check on the status of the Master Emerald, which was kept here at the time.

After arriving too late, Sonic, Tails and Knuckles saw Eggman stealing the Master Emerald, and Knuckles realized he had been tricked by the mad scientist. As the doctor made his escape with the Master Emerald, Knuckles guided Sonic and Tails to a hidden Warp Point to the Sky Sanctuary, from which the trio could witness the successful relaunch of the Death Egg. However, the two had to leave Knuckles behind as he was too exhausted from the previous two struggles. On their way through the Sanctuary, Sonic and Tails encountered two peculiar robots of the Eggman's; the Egg Robo, a robot in the image of Robotnik himself and Mecha Sonic, the third robotic doppelganger of Sonic, which, during the first two encounters with the heroes, copied the behavior of the doctor as witnessed on two previous occasions. On their third encounter, however, the original managed to defeat the copy. The resulting explosion managed to make a tall pillar nearby crumble, but Sonic managed to get on the Death Egg by running along the pillar as it was crumbling to pieces just in time.

Onboard the Death Egg, Sonic encountered Dr. Robotnik for the final showdown. The doctor attacked him with the giant Kyodai Eggman Robo, loosely made in his own image, powered by the Master Emerald. Sonic managed to defeat the contraption which finally destroyed the Death Egg for good, but the doctor still had a trick up his sleeve, as he managed to steal the Master Emerald again using a large blue, spaceship-like mech. In order to pursuit him, Sonic transformed once again in his Super/Hyper form, chasing the evil genius' across an orbit around the planet. After a long battle, Sonic emerged victorious against the doctor's spaceship-like mech, and later the doctor's jet-pack mounted escape mech, descending to Earth with the Master Emerald. In mid-flight, Sonic powered down to his regular form but was rescued by Tails, piloting the Tornado. The two then brought the Master Emerald back to where it belonged, thus allowing Angel Island to float into the sky once more before leaving Knuckles for the time being.

Some time after this, Sonic, piloting the Tornado personally, rescued Knuckles the Echidna after the latter's fight against the recently-reactivated Mecha Sonic from falling into the ocean. The two brought the Master Emerald back to Angel Island and the hedgehog and echidna parted ways once more.

Sonic Triple Trouble
In Sonic Triple Trouble, Dr. Robotnik, while running a final weapons test with the Chaos Emeralds, had an accident that scattered the emeralds across the planet.

After having gotten wind of Robotnik's incident, Sonic and Tails sprung into action and began searching for information on the Chaos Emeralds before Robotnik could reclaim them. The heroic duo soon learned however, that their quest would get more difficult than usual when they met suddenly met Knuckles the Echidna, who had been tricked by the doctor into helping him once more. As they got blocked by Knuckles, Sonic was told by the echidna that he would never get his hands on the Emeralds. As things got more confusing for Sonic and Tails, a dangerous treasure hunter by the name of Fang the Sniper also set his eyes on the mysterious gems, bent on stealing them for his own personal gain. Despite their many adversaries however, Sonic's resolve remained unshaken.

Over the course of their adventure, Sonic and Tails managed to race and battle their way through the world, retrieving the five of the Chaos Emeralds from the Special Stages, while dealing with and overcoming Fang and Knuckles's respective traps and ambushes along the way. When they arrived at the mad scientist's base, Sonic and Tails confronted Metal Sonic and then Fang. However, the treasure hunter was scared away when Robotnik arrived with his newest contraption.

In the end, the doctor's machines was destroyed by Sonic and Tails, who then found Knuckles imprisoned by the doctor. They freed him, and Sonic and Tails  made up on good terms with Knuckles once more, before talking off on the Tornado towards new adventures.

Sonic Labyrinth
In the 1995 game Sonic Labyrinth, Sonic was taking a nap on South Island, until he woke up in the afternoon. While thinking to himself, Sonic tried to get up and make a jump, but suddenly found himself unable to, as his feet felt heavier than usual. Looking carefully at his shoes, Sonic found, to his shock, Dr. Robotnik's symbol imprinted on the soles.

After inspecting his shoes, Sonic looked up again, only to see Dr. Robotnik's face. Having snuck up on him while Sonic was unaware, Dr. Robotnik proclamined triumphantly to the blue hedgehog that he had collected all the Chaos Emeralds. It turned out that the doctor had switched Sonic's regular shoes with his Slow-Down Boots, unique shoes made from the Chaos Emeralds' power, while the hero was sleeping, which disabled Sonic from jumping or running at higher speeds.

Stripped of both his speed and agility, Sonic was captured by Robotnik and put into the doctor's newly constructed super labyrinth on South Island, where Robotnik had set up his new fortress. While trapped in the labyrinth, Sonic could hear Robotnik's fortress expanding on South Island, slowly taking over the island. Though he had lost his greatest strength, Sonic refused to give up and soon after realized that he could still use his Spin Dash move to around and resolved to brave this labyrinth, stop the doctor, reclaim the Chaos Emeralds and regain his speed.

Despite his new pair of Slow-Down shoes, Sonic made his way through the labyrinth, and in the end, he defeats the mad scientist and making him flee from the island, while regaining the Chaos Emeralds and his regular shoes as well.

Sonic the Fighters
In the 1996 game Sonic the Fighters (also known as Sonic Championship), Doctor Robotnik went on to build a second Death Egg, known as the Death Egg II and again announced plans for world conquest. Luckily, Tails had recently built a rocket, the Lunar Fox, that could fly it's pilot directly to the new Death Egg. However, Sonic learned from Tails that it was a one-seater and it needed all of the Chaos Emeralds to take off. Therefore, Sonic and Tails entered a battle tournament where the winner got to collect all the Chaos Emeralds, which was in the possession of all the participants, and go to the Death Egg II and destroy it.

In order to gather all of the Chaos Emeralds, Sonic had to fight many friends and foes, old and new: Knuckles, Amy, Bark the Polar Bear, future Team Chaotix member Espio the Chameleon, his friend Tails, Bean the Dynamite and Fang. During the course of the tournament, Sonic managed to beat all the contestants and win their Chaos Emeralds.

Before Sonic could be off to launch the rocket, Robotnik showed up once again in a spaceship. An unusual ray hit Sonic that knocked him out for a few seconds. When he came back to his senses, the doctor was gone and before him stood a near-identical copy of himself. The hedgehogs fought, but in the end, the original hedgehog was victorious over his copy. Afterwards, Sonic headed back to Tails' workshop to launch the rocket, heading straight for the Death Egg II.

Upon his arrival, Sonic was "welcomed" by Metal Sonic. The two fought a tough battle, but Sonic could turn the tide in the middle of the fight by using the Chaos Emeralds' power to transform into Super Sonic once more, defeating his mechanical doppelganger again. He was then facing Robotnik himself, who built a battle suit for himself in order to face Sonic. At the same time, it appeared that the station's self-destruct sequence had been initiated, leaving the two combatants under time-pressure. However, since Sonic was still in his Super State, the mad scientist proved no match for him.

After having defeated Eggman, Super Sonic left the station in Tails' rocket, moments before it self-destructed and returned home.

Sonic 3D Blast
In Sonic 3D Blast, Sonic went on yet another adventure, this time traveling with Tails and Knuckles to Flicky Island, the eponymous island of the game. Having heard legends about the island's Flicky birds' close connections to the Chaos Emeralds, the trio journeyed to the island to find these birds, hoping they would lead them to the Chaos Emeralds. Once they arrived, however, Sonic and the others found the island in a pandemonium. They discovered that Doctor Robotnik was at his evil schemes once more, as he had established a base on the island and was trapping the helpless Flickies so they power his robots and be used to find the Chaos Emeralds, which were located on the island.

Enraged by Robotnik's actions, Sonic decides to save the Flickies, return them to their home dimension and find the Chaos Emeralds before the doctor could get them. Sonic eventually managed to rescue all the Flickies on the island and, with the help of Tails and Knuckles, managed to gather all of the Chaos Emeralds before the doctor could do so himself.

With support from the rescued Flickies, Sonic managed to get to the secret lair of the mad scientist, where Sonic confronted him in a final, lengthy battle. Ultimately, Sonic emerged victorious and managed to escape the lair in time. With the island now liberated from the evil genius' control, the Flickies thanked Sonic for his help and peace reigned over the island once more.

Sonic R
In the prelude to the 1997 Sega Saturn and Windows game Sonic R, Sonic and Tails went on a relaxing vacation where they hoped to take a break from their adventures. As the two of them were strolling down the road however, they caught news about the World Grand Prix. Despite Tails' urging, Sonic was not interested in participate in this racing competition as he knew he was the fastest. However, once he glimpsed at the list of registered participants, he saw Dr. Robotnik's name on the list as well. This caused a change of mind for Sonic, and he immediately ran off to register himself to the race. In the competition, Sonic had to face his friends Tails, Knuckles and Amy, as well as the scientist that was the reason for him joining in the first place. The evil genius planned to use Sonic to locate the Chaos Emeralds which were scattered around the race tracks and had brought with him robots to participate, both old and new: Metal Sonic and EggRobo, as well as Metal Knuckles and the ominous Tails Doll.

In the end, however, Sonic outraced them all and Dr. Robotnik did not get his hands on the Chaos Emeralds, proving himself once again as the fastest thing alive.

Sonic Adventure
In Sonic Adventure, Sonic was put up against an ancient water monster named Chaos who was under control of Dr. Eggman and prevented it from collecting all of the Chaos Emeralds.

While enjoying himself, traveling through Station Square, Sonic saw the Station Square Police fighting Chaos. Sonic then stepped in to fight Chaos, and defeated it. However, Chaos managed to escape through the drains, leaving Sonic without answers for what this was all about. The following day, while sleeping near a hotel's pool, Sonic awoke to see Tails' newest plane crash.

After finding Tails at Emerald Coast, he revealed to Sonic that his new plane was powered by a Chaos Emerald. Sonic then traveled with Tails to his workshop, as the fox wanted to show him one of his projects. Once they arrived, however, Eggman showed up. As Sonic insulted the doctor with some remarks, Dr. Eggman demanded the Chaos Emerald, but Sonic and Tails refused, leading to the doctor attacking them with the Egg Hornet. Though Sonic and Tails repelled the Egg Hornet, Eggman still snatched the Chaos Emerald and revealed Chaos, who he transformed into Chaos 1. As Sonic recognized the creature from the day before, Dr. Eggman revealed to him that he planned to make Chaos invincible with all of the seven Chaos Emeralds, and then use it to build Robotnikland upon Station Square. As the doctor then escaped, Sonic was determined to stop Eggman's plans, and Tails told him that if they could get the Chaos Emeralds before Dr. Eggman could give them to Chaos, the doctor's plan would amount to nothing. The duo therefore began a new search for the Chaos Emeralds.

After a while, Sonic and Tails managed to collect the first two emeralds in Windy Valley and Casinopolis respectively. After leaving Casinopolis, however, Dr. Eggman appeared and disabled Sonic and Tails with a knock-out gas, before stealing one of their Chaos Emeralds. As they came to their senses, Sonic was annoyed at the lost of the emerald, but also relieved that the other one was safe. Sonic and Tails then went ahead and found the next Chaos Emerald in Ice Cap. After that, however, they ran into Knuckles, who had been tricked into believing Sonic had stolen parts of the Master Emerald. Knuckles attacked and demanded the emeralds, but Sonic had no interest in reasoning with him, and the two of them began fighting. During the fight, Sonic dropped the two Chaos Emeralds, which were taken by Dr. Eggman, who had appeared and told how he tricked Knuckles. As Sonic berated Knuckles for being duped again, Eggman gave the two Chaos Emeralds to Chaos 2, transforming it into Chaos 4. Sonic and the others still managed to beat Chaos 4 though, and Eggman escaped to his Egg Carrier. After parting with Knuckles, Sonic and Tails tried to follow Dr. Eggman in the Tornado, but were shot down.

Sonic himself landed head-first on the beach near Station Square after being shot down. Concerned about Tails's whereabouts, Sonic hurried out to find his friend. He soon ran into Amy, much to his own dismay, who asked him to help her protect "Birdie", a Flickey she met earlier. Sonic, however, had no interest in that request, but Amy follow him regardless. Soon after, however, Sonic and Amy came under attack by ZERO. As Sonic got ready face the robot, Amy escaped into Twinkle Park, forcing Sonic to follow her. After passing through Twinkle Park, Sonic lost track of Amy. While wondering where she went off to, Sonic heard Amy yell, and saw her being kidnapped by ZERO. Sonic then began chasing after them, intending to cut ZERO off at the Mystic Ruins. (NOTE: Although Sonic's refusal of helping Amy's request with Birdie is predetermined by plot for her individual story, it displays a contradiction of Sonic's trait of never refusing to help those in need.)

Once at the Mystic Ruins, Sonic managed to corner ZERO, only for the robot to escape with Amy to the Egg Carrier. Frustrated at losing Amy again, Sonic tried to pursue the Egg Carrier through Red Mountain. As Sonic's chase reached a dead end, Tails appeared in the Tornado 2, powered by another Chaos Emerald. Relieved to see that Tails was well, the duo gave chase on the Tornado 2 and managed to land on the Egg Carrier. Once onboard the ship, Dr. Eggman to change its shape, thus halting Sonic's advances to the bridge. After the doctor insulted Sonic over the speakers, Sonic and Tails made it to the bridge through the Sky Deck. Shortly after, Sonic found Amy, only to see Eggman take a Chaos Emerald from Birdie, and then unleash E-102 Gamma on him while the doctor escaped. Before Sonic could destroy Gamma however, Amy stopped him, claiming it was her friend. Though confused, Sonic complied to Amy's request. As the Egg Carrier began to lose altitude, Sonic told Tails to take Amy to safety, while he chased after Eggman on his own.

After some difficulties, Sonic eventually found Eggman, but also saw to his shock that Chaos had become Chaos 6. Big the Cat also arrived and pointed out that his friend Froggy was trapped inside Chaos, and Sonic promised to help save him. After helping Big save Froggy, Sonic managed to defeat Chaos 6, only for Knuckles to appear as Eggman tried to escape. Sonic left Knuckles to finish Chaos, while he chased after Eggman. Following Eggman off the Egg Carrier, Sonic made a rough landing in the Mystic Ruins, where he found an ancient temple and a mysterious light that he thought was trying to show him something. Exploring the temple, Sonic found a mural depicting a monster, and was taken back in time to when the Altar of the Emeralds lied ruins. Confused, Sonic looked around and found Tikal trying to stop the catastrophe occurring, before being returned to the present. There, Sonic spotted Eggman and followed him, determined to end this conflict. Sonic eventually followed the doctor to the Final Egg, where he faced Eggman in his Egg Viper, and defeated him. As Eggman flew away in defeat, Sonic met up with Tails again, having seemingly saved the day.

After resting from all these ordeals, Sonic learned from Tails that Angel Island had fallen. As he arrived there, Sonic found both Knuckles and Eggman knocked down and learned from them that Chaos was still alive, had rebelled against Eggman, and now had six Chaos Emeralds. After Eggman left to get revenge, Sonic and Tails were about to head out to stop Chaos, but Sonic was then suddenly drawn into the past again. There, he saw the Knuckles Clan's attack on the Altar of the Emeralds, Tikal futile attempt to stop her clan and the event that drove Chaos to destroy the world to begin with. As Sonic came to Tikal's aid, he witnessed Tikal sealing herself and Chaos inside the Master Emerald.

Sonic was returned to the present, thinking he just snoozed for a second and headed out with Tails to find the last Chaos Emerald in the Tornado 2, but Chaos beat them to it and took the Chaos Emerald before their eyes. Sonic then returned to Station Square which was being attacked by Perfect Chaos. As Perfect Chaos destroyed the Egg Carrier 2, Tikal appeared before Sonic, and explained that the sadness and anger Chaos felt from her clan's attack was the reason for its current destructive behavior. As Perfect Chaos released the partially drained Chaos Emeralds, Tikal said they have to seal Chaos again, but Sonic responded that it would not work as Chaos' heart would still be full of rage and that it would not vanish if they just sealed it away again. Tails, Big, Amy and Knuckles then came to Sonic with all seven Chaos Emeralds, claiming that Sonic could still use their positive energy to stop Chaos. With everyone cheering him on, Sonic transformed into Super Sonic and defeated Perfect Chaos, while cleansing it of evil, thus returning it to a benevolent creature once more.

After his victory, Sonic watched with his friends as Chaos and Tikal departed to regions unknown to live in peace, with everything having returned to normal. Noticing Eggman making his escape, Sonic decided to head off himself once more, seeking out his next adventure.

Sonic Shuffle
In Sonic Shuffle, Sonic was hanging out with Tails, Knuckles and Amy, until they were suddenly transported into Maginaryworld. Afte landing in the Temple of Light, the group began questioning where they were, while Sonic just called it a “very strange place”. Here, they met a fairy-like being. Sonic asked who she was and she introduced herself as Lumina Flowlight, the person responsible for bringing them to Maginaryworld.

After introducing herself and the world to Sonic and the gang, she explained that they were brought here to help her save the Precioustone, the object that sustained Maginaryworld, which had been shattered by Void when he tried to steal it. Its pieces was then scattered to different part of Marginary World and had made their ruler and protector of the Precioustone, Illumina, vanish as well. Sonic listen on as Lumina explained that she needed him and the others' help to recover the pieces of the Precioustone, or Void’s darkness would spell the end of Marginary World. With everyone in agreement, Sonic willingly agreed to help Lumina save Maginaryworld.

The party began their adventure by recovering the Precioustone pieces from the different worlds within Maginaryworld, and restore the worlds affected by Void. Each time after collecting a Precioustone piece, Sonic and the others had a vision where they saw and interacted with Void. Sonic and the gang initially stood defiant against Void, with Sonic telling Void that he had no right to destroy Maginaryworld, and that this world was for everyone to enjoy. However, Sonic and the others began to see that Void showed signs of depression and loneliness which touched their hearts, and they began to think that there were more to Void than met the eye.

After Sonic and his friends had collected all the Precioustone pieces and returned them to the Temple of Light, they headed back to the temple when Void went there to seek out the Precioustone again. As Sonic, Lumina and the rest arrived at the temple to stop Void, Void claimed he just want to become whole, but never could. As Sonic began to see Void’s true nature, Void’s loneliness and despair reached its peak and he transformed into a monster.

Sonic, Knuckles Tails and Amy fought and defeated Void, but Lumina was lost in despair as the Precioustone was not recovering and began to lose faith. They others however tried to cheers up Lumina, and Sonic found Void in the form of a dark gem. The group now understood that Void and Lumina embodied the positive and negative aspects of dreams and were two halves of the same being. Sonic then explained to Lumina that she should not reject Void as the despair and emptiness that he embodied made it possible for people to have dreams.

With everyone’s help, Lumina realized that both positive and negative feelings were necessary for dreams to exist and Sonic handed Void over to Lumina, who now accepted Void. They then witnessed Lumina restoring the Precioustone, and Lumina and Void returning to their original form, Illumina. As Marginary World was restored to an even better place, Sonic and the gang heard Illumina explaining that it was her own despair that split her into Lumina and Void. After receiving Illumina's gratitude, Sonic and the others returned to their own world.

Sonic Adventure 2
In Sonic Adventure 2, Sonic first meets his fiercest rival, Shadow the Hedgehog. Here, Shadow was released by Dr. Eggman to assist him in his plans for world domination, and in order to achieve that, Shadow began hunting down the Chaos Emeralds.

After Shadow robbed a federal reserve bank and stole a Chaos Emerald, everyone else mistook him for Sonic. As a result, Sonic became wanted by Guardian Units of Nations (G.U.N.), and was eventually hunted down and captured by the military. Handcuffed and in custody, Sonic was brought onborad a Military helicopter to be transported. While over Central City, however Sonic managed to break free and take out everyone onboard, before escaping from the helicopter into the city.

After escaping G.U.N. and destroying a Bigfoot vehicle, Sonic met Shadow, who had just arrived at the scene with a Chaos Emerald. Realizing that Shadow was the one behind the false accusations, Sonic demanded an explanation and went to attack him. Instead, Shadow used Chaos Control to escape Sonic's attack. Shadow then revealed his name and title to Sonic, before disappearing in a flash. As he wondered what Shadow was, Sonic found himself surrounded by G.U.N. soldiers and robots, and was arrested once more.

Following his arrest, Sonic was brought to Prison Island, where he was locked up in a jail cell. Being locked up proved especially frustrating for Sonic, due to him having such limited space to move around on. Luckily, the following day, Sonic found Amy arriving at his jail cell, who revealed that she and Tails had come to break him out. As Sonic explained that it was Shadow's fault that he was here, Amy said that Shadow was on the island. Sonic tried to ask Amy about Shadow, but as she said that she would reveal more if he married her, Sonic changed his mind and refused. Nevertheless, Sonic was freed from his cell by Amy, and he learned that Eggman was behind it all when Amy said that Shadow was with the doctor. No sooner, Sonic quickly took off to find his imposter. After a while, Sonic found Shadow, and the two hedgehogs foguht each other until they learned that the island was about to explode. Fortunately, Sonic managed find to Tails and Amy and escaped the island with them just before it exploded.

Back in Central City, Sonic, Tails and Amy saw Eggman's broadcast, where he revealed the Space Colony ARK and displayed the Eclipse Cannon by blowing up half of the Moon, before demanding total world control within 24 hours or he would fire the cannon at Earth. Seeing this display of power, Sonic realized that this was the reason why Eggman was collecting the Chaos Emeralds. As Tails began to plan how to track Eggman down, the police arrived. Sonic however, led the police away to give Tails time to work. While being chased by the police, Sonic contacted Tails to hear the fox's progress, and heard from him that they could use the communication link to Eggman in the President's limousine to find Eggman's location. The two of them met up inside the president's limo, where they discovered that Eggman was on board the ARK. As the duo prepared to leave the limo, Sonic told the president to leave the problem with Eggman to them.

Having determined the scientist's location, Sonic, Tails, and Amy were led to the pyramid that Eggman's base was located at by Knuckles. Hoping to find a space ship that could take them to the ARK inside the base, Sonic planned to get to the Space Colony ARK from there and destroy the Eclipse Cannon. After the group had entered and infiltrated the base, they came across a door blocking the path to the center of the base. Sonic therefore enlisted Knuckles to find the keys to unlock it, confident he would succeed. After getting access to the launch pad for a space shuttle, Eggman amushed the group and unleashed the Egg Golem on them, which Sonic chose to face alone. Sonic defeated the robot, and joined the others in the space shuttle just before liftoff.

While en route to Space Colony ARK, the group's space shuttle hit a stray asteroid, causing the cargo bay to open and releasing the Emerald Shards that were stored there. Knuckles, wanting to salvage the Emerald Shards, tried to take control of the shuttle, only to cause them to crash land on the ARK. Once onboard, Sonic and Tails began their mission to destroy the Eclipse Cannon. For this, Sonic received a fake Chaos Emerald from Tails that he could use to destroy the cannon from the inside out when Tails turned off the power. When Sonic arrived at the cannon control room, however, he was contacted by Dr. Eggman moments before he could insert the fake Emerald into the cannon. Eggman then demanded to Sonic that he handed over the final Chaos Emerald to him or he would kill Amy.

When he arrived in the ARK's central control room, Sonic thought he could trick Eggman into taking the fake Emerald. Eggman, however, saw through his ruse, and Sonic was captured in a capsule set to explode. Sonic then told Tails to finish things and Amy to care of herself, before he was ejected into space. Before the capsule could explode, however, Sonic managed to use Chaos Control with the fake Emerald and send himself back to the ARK. There, Sonic met Knuckles and asked him find Tails and Amy while he went to the cannon to destroy it with the fake Emerald when it was going to fire. On his way there, Sonic met Shadow again and explained to him how Chaos Control saved him. Sonic then told his dark doppelganger about himself, before they began fighting. After Sonic won, he managed to destroy the Eclipse Cannon just before it fired.

When Sonic returned to the main control room of the Space Colony ARK with Knuckles, they discovered that the station gave off vibrations. Here, Sonic met Rouge, who told them that the ARK was on a collision course with Earth. Sonic and all the others then witnessed a recording of Gerald Robotnik that announced to the world that the ARK would crash into the planet and destroy it, wiping out the human race as his revenge at the world for the death of his granddaughter, Maria. Banding together with Eggman, the group came up with plan of using the Master Emerald to deactivate the cannon's core, which was powered by the seven Chaos Emeralds, to stop the Space Colony's crash course. With the plan set, Sonic told them to leave it to him.

With everyone working together, Sonic and Knuckles made it to the core, but they were then intercepted by the Biolizard. Suddenly, Shadow showed up and held off the Biolizard, while Sonic and Knuckles deactivated the Chaos Emeralds. In response, however, the Biolizard teleported outside the ARK and merged with it, becoming the Finalhazard and kept the ARK on its collision course. Determined to stop this catastrophe, Sonic and Shadow used the Chaos Emeralds to become Super Sonic and Super Shadow, and together, they defeated the Finalhazard. The duo then stopped the ARK by sending it back into orbit with a massive Chaos Control, but Shadow fell into the atmosphere from exhaustion, and Sonic presumed he had died.

As Sonic came back on board, he sadly informed them of Shadow's fate, before giving Shadow's Inhibitor Ring that he had found to Rouge, and assured her that Shadow was a great hero that he would never forget. As Sonic processed Shadow's death, Amy asked him what the matter. Sonic, however, assured her that it was nothing and suggested that they all went back home. With the rest of the gang having left, Sonic bid farewell to his worthy opponent as he took his leave as well.

Sonic Advance
In Sonic Advance, Sonic joined forces with Tails, Knuckles and Amy to stop Dr. Eggman from obtaining the seven Chaos Emeralds, as the doctor's resumed his hunt for the Emeralds. In the end, Sonic and his friends managed to beat Eggman to it and got the Chaos Emeralds first. Over the course of their adventure, Knuckles and the others chased after Eggman while defeating the doctor on a number of occassions. The group eventually followed Eggman into space, where they confronted him in the X-Zone. After they defeated the Egg X, Sonic chased after Eggman when the scientist tried to escape, only to stop at the edge of the station when Eggman fled to the Moon. Not intending to let Eggman get away, Sonic used the Chaos Emerald to transform into Super Sonic and followed him. On the moon's surface, Super Sonic faced Eggman and his Super EggRobo and defeated him. After the fight, Sonic seemingly disappeared, but then reappeared a few days later (still in his Super State) as he flew through the sky, where he met Tails in the Tornado.

Sonic Advance 2
In Sonic Advance 2, Dr. Eggman kidnapped Tails and Knuckles as he tried again to build the Eggman Empire. When Sonic learned about his friends kidnappings, however, he immediately headed out to save them. Along the way, Sonic met Cream the Rabbit and Cheese for the first time, who were also held hostage by Dr. Eggman. Sonic managed to save Cream and Cheese from Eggman, and he was amazed by the young girl's manners when she thanked him. When Sonic tried to leave them, Cream and Cheese instead joined him on his adventure as Eggman had kidnapped Cream's mother, Vanilla the Rabbit, too and they wanted to save her.

Shortly afterwards, Sonic rescued Tails from Eggman, who also joined Sonic when he tried to leave him. Later, Sonic confronted and defeated Knuckles, who was tricked by Eggman into fighting Sonic. Sonic chided Knuckles for being tricked by Eggman again and tried to leave him, but Knuckles joined him regardlessly. After seemingly beating Eggman, Cream found Vanilla, only to have her kidnapped by Eggman again in his new mech, leaving Sonic frustrated for being too late. Seeing Cream cry at the loss of her mother, Sonic transformed into Super Sonic and pursued Eggman. Super Sonic eventually defeated Eggman's mech and escaped with the capsule containing Vanilla.

As they fell through the atmosphere, Super Sonic tried to break his and the capsule with Vanilla inside's fall, but the reentry tore the capsule apart and Super Sonic powered down to normal. As Vanilla fell through the sky, however, Sonic managed to catch her and brought her safely back down to the ground. There, Sonic reunited Cream and her mother, and he thanked Tails and Knuckles for their help. Sonic did not stay for long however and soon ran off again, looking for new adventures.

Sonic Advance 3
In Sonic Advance 3, while hanging out with Tails, Sonic witnessed Dr. Eggman splitting the Earth into seven regions with Chaos Control, with the doctor planning to turn each region into a part of the Eggman Empire. Sonic then immediately headed out with Tails to stop Dr. Eggman, restore the world and collect the Chaos Emeralds before Eggman could use them to build his empire.

As Sonic and Tails traveled across the different regions, they came across Knuckles, Amy and Cream who joined them in their mission. Along the way Sonic also faced Dr. Eggmans newest creation, Gemerl, a rebuilt version of Sonic's old friend Emerl, on several occasions. After having made it across the seven different regions and having collected the seven Chaos Emeralds, Sonic and his friends made it to the Emerald Altar. After defeating the Hyper EggRobo, Sonic and his friends used the Master Emerald to return the world to normal. As Sonic chased after a defeated Eggman and Gemerl, however, Gemerl betrayed Eggman, took the seven Chaos Emeralds from Sonic and transformed into Ultimate Gemerl. Seeing what had to done, Sonic took the Chaos Emeralds which Ultimate Gemerl had discarded and transformed into Super Sonic. Putting aside their differences to fight a common enemy, Super Sonic and Eggman joined forces, and together, the unlikely duo defeated Ultimate Gemerl in space, which resulted in a large explosion.

Following the explosion, Sonic passed out, but woke up back on Earth and found himself surrounded by his friends who had awaited his return. After seeing Eggman leaving, Sonic then headed out himself, searching for new adventures.

Sonic Heroes
In Sonic Heroes, Sonic was running around in a desert on his own private tour across the globe, until Tails and Knuckles appeared in the Tornado 2. As Sonic caught up with his friends, Tails revealed that Dr. Eggman had sent them a letter. In the letter, Eggman claimed to have created "the ultimate weapon" that would let him take on the world, and he challenged Sonic, Tails and Knuckles to stop him within three days time. After having read the letter, Sonic, confident as ever, said to Tails and Knuckles that he would not miss this challenge for anything. He then headed out with Tails and Knuckles right behind him, officially forming Team Sonic.

Sonic and the gang began their quest by tracking down Dr. Eggman. They first met the doctor after Ocean Palace where he attacked them in the Egg Hawk. Eggman told the team that their efforts were futile, but Sonic remarked to the doctor that he was the one who fought in vain, and Team Sonic defeated the Egg Hawk, though Eggman escaped. Following their victory, Team Sonic tracked Eggman to Grand Metropolis. Seeing that Eggman's robots had taken control of the city, Sonic told his team that they would find Eggman and show him the power of teamwork. After liberating the city from Eggman's control, and escaping the Power Plant, however, Team Sonic came across Team Rose, with Sonic being surprised to see Amy there.

Sonic and his team were forced to briefly fight Team Rose, but Sonic managed to use the fight as a distraction to escape Amy. When they arrived in Casino Park after escaping Team Rose, Sonic talked with his team about Amy's persistence. Sonic then casually proposed they took some time off, but was pressed on by Tails as they only had 24 hours left to stop Eggman. After passsing through the city, Team Sonic was attacked by Eggman's Robot Carnival. Having dealt with the robots hordes, the team chased Eggman to Rail Canyon. Having only until sunset to stop Eggman, Sonic was through playing games, and ordered his team to go full speed ahead to the terminal station. After they made it to Bullet Station and destroyed Eggman's base, the team found Eggman in the Egg Albatross, just before their time limit ran out, and Sonic told the doctor that he was finished as they charged into battle. Though they managed to destroy the Egg Albatross, Team Sonic discovered that the Eggman they had been chasing was a fake and that their challenge letter was meant to distract them while Eggman launched his Egg Fleet. Enraged, Sonic ran off in hot pursuit of Dr. Eggman, with Tails and Knuckles following him.

Following the revelation, Team Sonic resumed their chase after Dr. Eggman. After having chased Eggman through the jungle, Team Sonic encountered Team Dark. Amazed at seeing that Shadow was still alive, Sonic heard that Team Dark was after Eggman as well, before being warned not to get in their way. Sonic, however, told Team Dark that they were after Eggman as well, and, after trash-talking with Shadow, Sonic and his team began fighting Team Dark. After the battle, Sonic saw Eggman and Shadow head towards Hang Castle and decided to follow suit. As they arrived on the haunted grounds, Tails expressed his doubts about their route, but Sonic assured him that they were on the right track. After Team Sonic had infiltrated the castle and escaped Mystic Mansion, they were attacked Eggman and his Robot Storm. Sonic, however, mocked the doctor by calling him a joke for trying to stop them now, before dispatching the robotic forces.

Fllowing the fight, Team Sonic made it to the Egg Fleet, where Sonic was ready to start the party. After traveling across the flagships, Sonic and his team made it to Eggman's headquarters, the Final Fortress, where they destroyed the flagship's core. Afterwards, Team Sonic found Dr. Eggman, with Sonic telling the doctor that they had him beat, before fighting Eggman in his Egg Emperor and defeating him. After heavily destroying the Egg Fleet, Sonic disagreed with Knuckles about how close they cut it this time, and was tease by Knuckles with the fact that he would not have made it through this adventure on his own. Regardless, Sonic agreed with Knuckles on it, and thanked both him and Tails for all their help. Once he was finished, however, Sonic saw Amy closing in on him. Not intending to be the target of Amy's affection, Sonic left Knuckles and Tails behind as he tried to escape Amy.

Shortly after finishing their mission, Team Sonic and the other teams witnessed the return of Metal Sonic (in his Neo Metal Sonic form), who had been staging each team's adventures and impersonating Eggman so he could copy their data in a plan to achieve world domination himself. Neo Metal Sonic then underwent a massive transformation into Metal Madness to gain the power necessary for this task. Seeing that the teams had all the Chaos Emeralds, the real Dr. Eggman came up with the plan of using them against Metal Sonic. Though their chances of winning were slim, Sonic volunteered to go up against Metal Sonic alone, but Tails and Knuckles insisted on going with him, while the other teams volunteered to buy them some time. Aceepting everyone's help, Sonic proclaimed they would show Metal Sonic the real super power of teamwork. Team Rose, Team Chaotix and Team Dark then fought Metal Madness, while Team Sonic charged the Chaos Emeralds.

When they were ready, Metal Madness assumed his ultimate form, Metal Overlord, and took off to the skies. Sonic then transformed into Super Sonic, whilst granting Tails and Knuckles Super Shields. The trio then followed Metal Overlord into the sky, and together, they defeated the metallic monster. Back on the flagship, Metal Sonic, now reverted back to normal, questioned Sonic why he could never defeat him, and Sonic simply said it was becasue they were heroes. Seeing Amy approached him, Sonic told his metallic counterpart that he would be ready for a rematch anytime and took his leave with Tails. Not long after, Sonic was reunited with Knuckles, and he headed out with his team to search for their next adventure.

Shadow the Hedgehog
In Shadow the Hedgehog, Sonic worked with most of his friends and G.U.N.'s forces to repel the Black Arms invasion of Earth. He often appeared during Shadow's Hero Missions where he helped Shadow in his fight against the Black Arms and their leader, Black Doom.

Westopolis
While fighting the Black Arms in Westopolis, Sonic came across Shadow, who was looking for the Chaos Emeralds. After greeting his rival, Sonic told Shadow about the Black Arms and asked for his help in taking them out.

In the Hero scenario, where Shadow accepted Sonic's request, Sonic told Shadow how impressed he was by Shadow's performance after having completed their objectives. Though Shadow rebuked Sonic's friendly attitude. Sonic told the black hedgehog that he expected that response, and suggested a friendly face-off, but was rudely declined. After Doom's Eye arrived and told them where the next Chaos Emerald was, Sonic enthusiastically ran off to its location with Shadow.

Lethal Highway
Having arrived at Lethal Highway before Shadow, Sonic had found the Black Tank, which contained a Chaos Emerald the Black Arms had taken. As Sonic chased after the Black Tank when it made its escape, he met up with Shadow and asked for his assistance in finishing off the Black Tank.

In the Hero scenario where Shadow agreed to help Sonic, the two managed to destroy the Black Tank. However, as the two of them moved in to collect the Chaos Emerald, Sonic and Shadow was confronted by Doom's Eye, who summoned the Black Bull to stop them. Despite the beast's threat, however, Sonic was excited to fight the monster. Eventually, Sonic and Shadow defeated the Black Bull and claimed the Chaos Emerald.

Mad Matrix and Death Ruins
In the Hero scenario of Mad Matrix and Death Ruins, Sonic had learned that the Black Arms were heading out to the Space Colony ARK, and decided to follow them there. With a spacecraft provided by Tails, Sonic went on his way to the ARK alone. While passing through Iron Jungle, however, Sonic came across Shadow. After giving Shadow a friendly greeting despite his rival's dismay at seeing him, Sonic informed Shadow of the Black Arms' activities and invited him to come with him to the Ark. Shadow accepted Sonic's offer, and the two of them took off.

Sky Troops
In the Hero scenario of Sky Troops, Sonic had learned that the Black Arms were heading out to the Space Colony ARK, and decided to follow them there. With a spacecraft provided by Tails, Sonic went on his way to the ARK alone. While passing through Iron Jungle, however, Sonic came across Shadow. After giving Shadow a friendly greeting despite his rival's dismay at seeing him, Sonic informed Shadow of the Black Arms' activities and invited him to come with him to the Ark. Shadow accepted Sonic's offer, and the two of them took off.

As Sonic and Shadow approached the ARK in their spacecraft, Sonic was excited to see through the windshields that the Black Arms' forces were waiting for them. Inviting Shadow to join him, Sonic hurried outside to engaged the enemies, before being joined by Shadow.

Space Gadget
When Sonic and Shadow made it onboard the Space Colony ARK as they followed the Black Arms to the ARK, Sonic saw that they were in familiar surroundings, and tried to make Shadow recall the time they race each other there. Sonic then challenged Shadow to a race through Space Gadget to the Chaos Emerald onboard the ARK just for old times sake.

In the Hero scenario, where Shadow accept the challenge, Sonic was beaten in the race and Shadow claimed the Chaos Emerald. As the two of continued to make their way through the ARK's interior, Sonic caught a glimpse of the Black Comet. When Shadow asked what it was, Sonic explained the Black Comet to Shadow, before he realized that Shadow suspected that the Black Comet was connected to the Black Arms. As Shadow suddenly sensed the Black Arms on the Black Comet, Sonic and Shadow decided to head to the Black Comet.

Lost Impact
In the Hero scenario of Lost Impact, Sonic made it onboard the Space Colony ARK with Shadow as they chased the Black Arms to the ARK. As the two hedgehogs continued their way through the ARK's interior, Sonic caught a glimpse of the Black Comet. When Shadow asked what it was, Sonic explained the Black Comet to Shadow, before he realized that Shadow suspected that the Black Comet was connected to the Black Arms. As Shadow suddenly sensed the Black Arms on the Black Comet, Sonic and Shadow decided to head to the Black Comet.

Final Haunt
After traveling from Space Colony ARK, Sonic and Shadow made their way to the Final Haunt on the Black Comet, the two of them having planned to stop Black Doom and the alien invasion of Earth.

Hero Scenario
In the Hero scenario also being the most heroic scenario, Sonic and Shadow began a mad hunt after Black Doom upon their arrival. After obtaining another Chaos Emerald, Sonic and Shadow finally found Black Doom, and Sonic told the alien overlord that the game was over. Sonic and Shadow then confronted Black Doom in a battle for their lives, and were victorious. As Shadow took the final Chaos Emerald from Black Doom, Sonic stood with full support by Shadow's side, as Shadow pronounced that he would use the emeralds to stop the Black Arms.

Dark Scenario
In the Dark scenario, Sonic was betrayed by Shadow when he abandoned their original goal and began aiding the Black Arms. In the last minute, Sonic encountered the G.U.N. Commander in the Diablon, and decided to team up with him to stop Shadow. As Shadow arrived before them, Sonic and the G.U.N. Commander confronted Shadow, with Sonic questioning his rival of why he sided with the Black Arms. As Shadow revealed that his only interest was to beat Sonic, Sonic was amused to face Shadow despite the circumstances, and told him to bring it on. Despite his best efforts, however, Sonic was utterly defeated alongside the G.U.N. Commander, and Shadow took the final Chaos Emerald from them. As he lay in defeat, Sonic told Shadow in a upbeat tone that he did not think he had in him to do this, before Shadow announced to him that he was now the most powerful hedgehog in the world.

Black Comet
In the Dark scenario of Black Comet, as Shadow decimated G.U.N.'s invading forces on behalf of the Black Arms, Sonic arrived and decided to team up with the G.U.N. Commander in the Diablon to stop Shadow. As Shadow arrived before them, Sonic told Shadow that he could not let him go like this, and was ready to face his rival, even when he was threatened with death. Despite his best efforts, however, Sonic was utterly defeated alongside the G.U.N. Commander, and Shadow took the final Chaos Emerald from them. As he lay in defeat, Sonic asked Shadow in confusion of why he was siding with the Black Arms, before Shadow proclaimed himself as the servant of Black Doom.

G.U.N. Fortress
In the Dark scenario of GUN Fortress also being the darkest scenario in the game, as Shadow ravaged through the GUN Fortress on behalf of the Black Arms, Sonic arrived and decided to team up with the G.U.N. Commander in the Diablon to stop Shadow. As Shadow arrived before them, Sonic told Shadow that he could not let him go like this, and was ready to face his rival, even when he was threaten with death. Despite his best efforts, however, Sonic was utterly defeated alongside the G.U.N. Commander, and Shadow took the final Chaos Emerald from them. As he lay in defeat, Sonic asked Shadow was he was planning to do with the Chaos Emeralds, only to hear that his rival had decided to use them to destroy the Earth.

Last Story
In the last story, Sonic arrived with Tails, Knuckles, Amy, Rouge and Dr. Eggman to stop Shadow from giving Black Doom the Chaos Emeralds and he told Shadow to give the emeralds to him. Black Doom however, took the emeralds himself and used an enhanced Chaos Control to transport the Black Comet to the surface, something which Sonic instantly recognized. Having heard Black Doom intention to use humans as energy sources for his kind, Sonic intended to stop Black Doom, but they all soon fell prey to a nerve gas which left them paralyzed, and Black Doom unleashed the Death leeches to prey on them. Shadow however, proved to be immune to the gas and as he left to pursue Black Doom, Sonic told him that he was their only hope left.

Sonic and the others eventually managed to escape the Black Comet and find some shelter from where they cheered Super Shadow on as he fought and defeated Devil Doom. He then witnessed Super Shadow sending the Black Comet back into space and blowing it to pieces with the fully charged Eclipse Cannon. With Shadow having saved the world, Sonic was impressed by the black hedgehog's victory and joined the others for a laugh as an enraged Knuckles chased Eggman around.

Sonic Battle
In Sonic Battle, Sonic and his friends work together to raise an ancient and all-powerful robot named Emerl, and as well as protecting it from Dr. Eggman who wanted to use it for another attempt at world domination. During the adventure, Emerl would come to see Sonic as a father-figure.

While on a boring stroll, Sonic found a robot called the Gizoid lying on Emerald Beach. As Sonic examined it, it started to move. It told Sonic to show his power, and Sonic displayed some fighting moves, thus it formed a Link with him. Thinking that the robot was broken, Sonic decided to take it to Tails to get it examined, but he ran into Shadow who demanded that Sonic handed over the Gizoid, but he refused. After fighting and defeating him, Shadow told Sonic to keep the Gizoid from Eggman and left. As Sonic wondered about where Eggman fit in all of this, Tails arrived and Sonic introduced him to the Gizoid. Having also spotted Rouge at the beach, Sonic told Tails to take the Gizoid to his lab, while Sonic located Rouge. Finding Rouge on the beach, Sonic asked her what she wanted and learned she and the goverment were after the Gizoid as well. Rouge then wagered with Sonic that he would have to team up with her if she beat him in a fight, but Sonic made her leave after he defeated her. Returning to Tails’ Lab to check up on Tails, Sonic encountered an E-121 Phi and defeated it. Worried that Tails could be hurt, Sonic got to the lab and luckily found Tails unharmed. Tails then revealed to Sonic that the Gizoid developed with each Chaos Emerald inserted into it and that it could copy fighting moves. Thrilled by these revelations, Sonic decided to train it.

After some training, Sonic and Tails decided to go see if Knuckles had a Chaos Emerald and Sonic decides to name the robot Emerl. On the way there, they took care of a E-121 Phi and were attacked by Chaos Gamma, which Sonic mistook for Gamma, but they defeated it. When they arrived at Knuckles’s, Knuckles mistook Emerl for a E-121 Phi and tried to attack him, despite Sonic trying to explain the situation. After Emerl defeated Knuckles, Sonic got his Chaos Emerald and they inserted it into Emerl, who thanked Sonic afterwards and called out for more battles, much to Sonic’s amazement.

Sonic continued training Emerl for a while, until Tails decided to take Emerl to Central City to fully examine him, following a sparring match between them. When they return, Sonic learned from Tails and Rouge that Emerl was a weapon of mass destruction, which was why Eggman wanted him, but Sonic refused to believe it. Sonic suggested they could reprogram him, and Rouge said that they could reset Emerl by inserting all seven Chaos Emeralds into him and giving him an unknown keyword. Sonic questioned Rouge why she was helping, and she said that it was the best for the world (and herself) that Eggman did not get a hold of Emerl. Rouge then made Sonic introduce her to Emerl by forming a Link with her, but she then suddenly left. When Knuckles then arrived upon Tails's request, Sonic told Knuckles what had happen, before beginning to tease him by ordering Emerl to ignore Knuckles, which the echidna hated. This eventually let to a fight between Sonic, Knuckles and Emerl, which Sonic gladly welcomed.

Sonic continued Emerl's training, but it was cut short when he saw Amy coming and ran away. He later returned and learned that Rouge had stolen Emerl, due to the earlier Link he formed with her. Sonic soon after, however, found Emerl with Rouge and engaged her in battle, intending to protect Emerl and get him back. As Tails and Knuckles then came to Sonic's aid, Rouge surrendered Emerl to Sonic, as she thought Emerl was more trouble than he was worth.

Some time after, Sonic left Emerl with Tails for a while, but when he returned, he learned that Emerl had been training with Knuckles and that Knuckles had been tricked by Eggman again.

Later on, Sonic and Emerl was approached by Amy again, who viewed Emerl as hers and Sonic’s "baby". As Sonic faced Amy’s wrath about how Sonic had been raising Emerl, Emerl made a bad choice of words and Sonic immediately ran off. He later returned to find Emerl with Amy, and she told Sonic that he had no excuse for marrying her now, since she had helped raising Emerl. Sonic then told Amy to close her eyes, but ran off again once she closed them.

Sonic and Tails later left Emerl in Amy's and Cream’s care, as the two of them checked out a lead on a Chaos Emerald, which later turned out to be fake. Sonic was then contacted by Eggman who said that he held Cream and Emerl hostage, but because the two of them had escaped, Sonic did not believe him. He soon after saw Eggman captured in his own "spiky rodent trap" by Emerl and Cream on-screen, and headed out to pick the pair up.

Sonic was later approached by Shadow again. Sonic thought that Shadow was here to capture Emerl, but it was not his intention. Shadow said that Emerl was close to awakening his full power, as he only needed one more Chaos Emerald and that he could bring the end of the world. Sonic, however, believed that Emerl would not do that, as Shadow was the ultimate top secret weapon of the government, and he had saved humanity at one point. As Shadow continued to brush off Sonic's arguments, however, Sonic gave up on trying to convince Shadow and let him have Emerl, who had just arrived, having been attracted by Shadow’s Chaos Emerald and Shadow restated his statement. Unshaken by this, Sonic let Emerl go with Shadow, believing he would learn who he really was with Shadow’s help.

With Shadow's help, Emerl was reset, and later came to fight Shadow. However, Sonic arrived soon after to fight Emerl along Shadow as well to test the robot's abilities to the fullest. After the fight, Emerl thanked Sonic and Shadow for all their help. Having seen that Emerl no longer needs him, Sonic told Emerl to live his life to fullest on his own, but not before he told him that his punches needed some work.

Later on, Sonic was having an conversation with Emerl, when Eggman suddenly appeared, and Sonic asked the doctor if he was back for Emerl. Eggman, however, announced that he had no use for Emerl anymore, and that he had finished installing his Final Egg Blaster on his newest Death Egg, which he would use to conquer the world. As Eggman made his escape, Sonic and Emerl met up with Tails, who had caught seen the Death Egg at Holy Summit, and Sonic decided to head there while Tails brought a transporter to the Death Egg with them. Arriving at Holy Summit, Sonic met up with Knuckles, who revealed that Chaos had appeared, which was sign that they were in big trouble, though Sonic was not worried. Tails then appeared with the transporter, but revealed that only one of them could be sent to the Death Egg and stop Eggman at the time, so Sonic suggested that Emerl should go, which he accepted.

When Emerl left for the Death Egg to stop Eggman, Sonic and his friends watched Emerl through a monitor on the Death Egg and cheered him on. After witnessed Emerl defeating Eggman, Sonic saw Eggman firing the Final Egg Blaster, destroying some stars. This great display of power caused Emerl to revert to his original programming and Eggman tried to assume control over Emerl, but he knocked Eggman away and prepared to fire the Final Egg Blaster on the Earth. As Sonic tried to order Emerl to stop, the Master Emerald appeared, and Sonic planned to travel to the Death Egg with the Master Emerald and use it to negate the Chaos Emeralds' energy inside Emerl. With the transporter back online and everyone urging him on, Sonic was teleported to the Death Egg, but Emerl smashed the Master Emerald upon seeing it. Tails then told Sonic that he could reverse Emerl's programming by inflicting enough damage on him, but it would destroy Emerl. Seeing no other choice, Sonic, with a heavy heart, engaged Emerl in a high speed battle. Seeing the overwhelming strength of Ultimate Emerl, Sonic decided to fight at full strength and defeated the Gizoid.

As he began to break down, Emerl thanked Sonic and his friends for everything, but, in a rare chase of visual sadness, emotional distress and denial, Sonic tried to assure Emerl that everything would be fine, promising the Gizoid lots of fun together, but to no avail, and Emerl disappeared before Sonic’s eyes. Sonic then returned to the Earth and found Cream crying over Emerl’s death, but Sonic told Cream that Emerl was still with them in the Emerald Shards. As Tails wondered if they would ever see Emerl again, Sonic, after a moment of silence, assured them positively that they would.

Sonic Rush
In Sonic Rush, Sonic came across Dr. Eggman during one of his casual runs, who claimed that he would soon possess “the ultimate power”, but Sonic assured him confidently that he would stop him. After defeating Eggman, Sonic saw that he dropped a Sol Emerald, but then suddenly he met Blaze the Cat, the guardian of the Sol Emeralds, who appeared in a burst of flames, took the emerald and left. Sonic later met up with Tails and explained about what he had just witnessed. While Tails was worried, Sonic was getting pumped up about this new challenge, and the duo headed out to stop Eggman.

At the Water Palace, Sonic ran into who he believed was Dr. Eggman, but the villain revealed himself to be Dr. Eggman Nega, a new foe that had teamed up with Dr. Eggman. After defeating him, Sonic thought it was simply Dr. Eggman in a new disguise, but Tails was not so sure. The two of them then headed to Tails’ workshop, where they learned that there was a rift in the space-time continuum that threatened reality itself. While Tails thought that Eggman Nega had something to do with, Sonic thought that Blaze might also be a part of this. As they searched for information and fought Nega, Sonic heard from Vanilla that Cream was together with Blaze and she told them where to find them. After thanking Vanilla for the info, Sonic ran off to find Blaze and get some answers.

After a lengthy search, Sonic and Tails came to a path closed by rocks. Before they could turn around though, Knuckles emerged from the rubble. As they questioned Knuckles of how he got stuck there, Sonic and Tails learned from Knuckles that he got trapped under the rocks when casing Blaze, before he took off in his rage. Ignoring Knuckles, Sonic and Tails continued through the path he had cleared, Sonic and Tails found Blaze and Cream, and Sonic asked Blaze if she knew anything about Eggman Nega. Blaze however, despite having been told by many to seek Sonic’s help, told him that she would deal with this crisis and Eggman Nega alone. Sonic, on the other hand, told Blaze that things did not work that way around here, but she firmly insistsed and left with Cream, but Sonic and Tails followed them.

While on their way tracking Blaze, Sonic regrettably ran into Amy who thought he was looking for her. Sonic tried to ask Amy if she had seen Blaze, but Amy initially thought Sonic was looking for Blaze because he liked her, and Sonic nervously asked Tails help. Amy eventually cooled down, however, and after providing directions for where Blaze went, Sonic immediately took off.

Sonic eventually tracked Blaze to the Dead Line where they faced both Eggmen. While Sonic insisted on participating, Blaze angrily refused his help and tried to force him to leave by fighting him. While battling, Sonic tried to make Blaze stop and said that she should not carry everything on her own shoulders, but to not avail. As their fight resulted in the two being exhausted, Sonic saw that Blaze was still willing to protect the Sol Emeralds even when completely worn down and understood that she must have had a rough past. He then told her not to handle too much on her own and be true to herself, and Blaze came to understand that she could rely on others. With their differences sat aside, they finally introduced themselves and became friends.

With Blaze on their side, Sonic learned that the space-time rift was because her world and Sonic’s world were merging with one another due to the Sol Emeralds having been stolen by Dr. Eggman and brought to Sonic's world. Hearing that Dr. Eggman and Eggman Nega were to blame, Sonic began to head out to confront Eggman Nega on behalf of Blaze to stop this, since she was not in shape to fight after their confrontation. Just before Sonic could leave, however, they noticed Cream was gone. The group learned from a letter left by Dr. Eggman, that the doctor held Cream hostage and demanded that Blaze came to Point W alone. As it was most certainly a trap, Sonic suggested that they got everyone together to help, but Blaze insisted on going alone because Cream was her friend. Sonic understood this and let Blaze go. While Tails questioned Sonic's choice, Sonic assured him by saying that believing in someone, is a part of friendship as well. Sonic himself then went to face Eggman Nega and managed to defeat him. In the aftermath of the fight, Sonic was welcomed back by his friends, but ran off when he saw Amy coming.

After collecting all seven Chaos Emeralds, Sonic came to Blaze’s aid as she was defeated by Dr. Eggman and Eggman Nega in the Egg Salamander and had all seven Sol Emeralds drained of their power, but the doctors left as he arrived to prepare for their coming fight. As Blaze despaired for failing her duty, Sonic told her that everything would be fine, and with him and his friends backing Blaze up, he assured her that with the friendships she had come to understand and embrace, the Sol Emeralds would never lose their power, and the Sol Emeralds recharged. Sonic and Blaze then used both sets of emeralds to become Super Sonic and Burning Blaze and together they defeated the Eggmans.

As the space-time continuum began to restore itself, Sonic and Blaze said their final goodbyes as they prepared to return to their respective worlds, but Sonic promised that they would meet again which Blaze hoped for. The two of them then shaked hands as a sign of friendship and respect as the space-time continuum pulled them apart and returned them to their own worlds. When Sonic returned home, he found Cream, who was sad over Blaze’s departure, but he cheered her up by telling her that Blaze would be back soon.

Sonic Rush Adventure
Sonic Rush also had a sequel called Sonic Rush Adventure (2007). The story began as Sonic and Tails were out in the Tornado investigating an unknown energy reaction in a storm, but they got sucked into a hurricane. Having crashed, Sonic and Tails washed ashore on Southern Island where they met Marine the Raccoon, a rash girl who dreamed of adventure. As they found themselves on an unknown island, Sonic and Tails decided to explore the surrounding islands. The next day, Sonic and Tails found Marine working on her own boat, but she ended up destroying it. The duo then helped Marine constructing a new boat and the trio began exploring the surrounding islands.

On their journey across the islands, the group was attacked by several robotic enemies. Sonic also encountered Johnny, who became his rival in water bike racing. When arriving at Coral Cave, Sonic met Captain Whisker and his pirate crew, who were the ones behind the attacks. Suddenly, Sonic saw someone who attacked the pirates and was surprised to see that it was Blaze the Cat. Despite this surprise meeting, Sonic gladly teamed up with Blaze to fight off Whiskers’ henchmen.

After the fight, the pirates escaped with the Jeweled Scepter, a powerful treasure from Blaze’s homeland which was hidden in Coral Cave and which Blaze tried to protect. Sonic questioned Blaze why she was here and not in her own world, but realized that they must have been transported to Blaze’s world during the storm. After explaining their story to Blaze, the group saw this meeting as a sign that both their worlds might be endangered by the pirates, now that they had the Jeweled Scepter. Sonic then suggested to Blaze that they should work together to get the scepter back, and she accepted it.

The four of them then traveled the sea in their search for clues to the pirates' whereabouts. After having tracked and lost the pirates at Haunted Ship, freeing the Vikings on Blizzard Peaks from the pirates' captivity, and uncovering the secrets of Sky Babylon, Sonic and the group managed to pinpoint the pirates’ hideout in some ancient ruins. Before heading in there, however, Sonic, Tails and Blaze decided to leave Marine behind as she could endanger the mission, but she objected. While Sonic and Tails tried to be gentle about the reason, Blaze bluntly said that she was a nuisance, to which Sonic and Tails silently agreed with her. This lead to Marine running off, crying and yelling at them. While Tails and Sonic felt it was a harsh comment, Sonic was sure that she would get over it.

At the pirates’ hideout, Sonic faced Whisker and his right-hand man, who is revealed to be Johnny, alongside Blaze. Despite beating them however, Whisker escaped and Sonic then saw that Marine was going after the pirates to prove herself, but ended up being caught by the Ghost Titan. Fortunately, Sonic came up with a plan to distract Whisker by letting Tails pretend the scepter was somewhere else on the ship while he and Blaze saved Marine. Sonic and Blaze then destroyed the Ghost Titan together and escaped, while the pirates went down with the collapsing ship. With Marine having reclaimed the Jeweled Scepter, the group headed back to Southern Island.

After collecting all seven Chaos Emeralds and Sol Emeralds, Sonic and Tails planned to return home, but they then learned that the Jeweled Scepter had been stolen again. An earthquake then occured and in the wake, the thieves revealed themselves to be Dr. Eggman and Eggman Nega in the Egg Wizard, and the group learned that they were the ones who created the pirates, so that they could use the Jeweled Scepters incredible power to build Eggmanland upon both worlds. Sonic and the gang headed out to confront the Eggmans but were too late as the villains tapped into the Power of the Stars with the scepter. As Eggman Nega taunted Blaze by treating to destroy her kingdom, Sonic kept Blaze calm for hers and her people’s sake. They then used the Chaos Emeralds and Sol Emeralds to become Super Sonic and Burning Blaze and they fought the Egg Wizzard. As they were about to win however, Eggman Nega tried to destroy them, along with the world, but Marine distracted them, and with Blaze’s aid, Sonic dealt the final blow and destroyed the Egg Wizard.

The next morning, Tails constructed a vessel for him and Sonic to return home in. As Sonic prepared to leave, Blaze suggested to him that the Sol Emeralds and the Chaos Emeralds were responsible for bringing them together again. Sonic was initially confused by her statement, but then said positively that they could never know for sure. As they were about to leave, Sonic said goodbye to Blaze and they shaked hands once more, signifying their growing friendship and respect. Just as they were about to take off, however, Sonic and Tails saw Marine coming in her new boat to say goodbye. While she was sad that they had to leave, Sonic and Tails promised her that they would meet again someday. With these final goodbyes Sonic and Tails headed back to their own world.

Sonic Riders
In Sonic Riders, Team Sonic arrived in Future City, as they searched for a Chaos Emerald, when suddenly a group of thieves on Extreme Gear, called the Babylon Rogues, revealed themselves. Tails read on his radar that the Emerald was in their possession and Sonic ran off to intercept them. After Knuckles knocked Storm the Albatross off his Type-S, Sonic grabbed the Type-S and decided to give chase to the Rogues by riding the Type-S himself. With some trouble, Sonic quickly grasped the control of the Extreme Gear, and went after their leader, Jet the Hawk. After exchanging some blows, Sonic passed by Jet, but was then quickly blown off the Extreme Gear by Jet, and the Babylon Rogues escaped. Sonic however, was thrilled to have found someone who could give him a challenge.

The next day, Sonic, Tails and Knuckles saw Dr. Eggman on the local monitors, announcing the EX World Grand Prix and that the entry fee for the contestants was a Chaos Emerald, with the winner getting the right to claim all seven. Sonic was initially suspicious about Eggman’s motives, but when he saw that the participants Dr. Eggman had rounded up were the Babylon Rogues, Sonic decided to enter the competition and uncover Eggman's plot.

After the qualifications rounds, Sonic was walking around with his team, openly admitting that he was not worried about Eggman's plans, when he suddenly ran into Amy, who had also signed up for the tournament, much to Sonic's discomfort. Sonic then listened to Tails explaining the legends of the Babylon Rogues after having seen the mark on Storm's Extreme Gear, how they lost their home island, Babylon Garden, and its treasure. After having hear the legend, Wave the Swallow came by and mocked the Blue Star Tails had created for Sonic (and placed a bomb on it), leaving Sonic disgusted by the way she acted. No sooner though, Sonic and the other hurried to next race after hearing the call.

Over the course of the competition, Sonic managed to advance through each round. Shortly before the semifinals, Sonic took his time to practice his Extreme Gear techniques. As Sonic was praised by Tails, they were interrupted by Jet, who mocked Sonic's attempts at mastering Extreme Gear, before leaving. While Sonic was angered by this, he could see that Jet was a good Extreme Gear rider and that he shound not underestimate him. Tails began to doubt the Extreme Gear he had made for Sonic, but Sonic faithfully assured him and told him not to worry.

Eventually, Sonic and his team made it to the finals. As he headed up to the podium with Jet and their Chaos Emeralds, Sonic receiving some final taunts from Jet, but Sonic promised Jet that he would not lose. At the end of the final race, Sonic was about to win, but Wave detonated the bomb under Sonic’s Extreme Gear, causing Sonic to lose. Lying dazed on the ground, Jet, having won the race, told Sonic that the dirt suited him, making Sonic furious at the outcome.

Sonic and the others were then left witnessing Jet claim and use the seven Chaos Emeralds in tandem with the Key to Babylon Garden to reveal Babylon Garden itself, with the intention of claiming its treasure. Eggman, however, stole the key so that he could take the treasure for himself, believing it to be technology that he could use to conquer the world. Calling his team, Sonic headed out to stop Eggman. Using the Tornado 2, Team Sonic arrived at Babylon Garden, where Sonic found Eggman. Before he went after Eggman, Sonic was given the Blue Star II by Tails. Thanking Tails, Sonic took off to catch the doctor, but was locked in a race with Jet, who was after Eggman too. Seeing this as a rematch, Sonic told Jet that he would show him what true speed really is.

Sonic eventually beat Jet and cornered Dr. Eggman, but stopped when Eggman revealed he held Amy hostage. Sonic, however, pulled out the same move Jet used on him and blew Eggman (and Amy) away. Sonic then took back the Key to Babylon Garden and handed it back to Jet, who viewed this as an act of pity. As the Rogues went to claim the treasure, Sonic decided it was time to leave, but then met Amy, who was furious at him for endangering her with the move he used on Eggman, and chased after Sonic with her Piko Piko Hammer. No sooner, Sonic and the others heard a roar and decided to check it out. As the group got inside Babylon Garden, Sonic and the others saw that the Babylon Rogues had awoken the Babylon Guardian and were forced to fight it.

After beating the Babylon Guardian, Sonic and Jet found the Treasure of Babylon, which was revealed to be a Magic Carpet, much to the disappointment of Eggman, who had just arrived to steal it. With the whole ordeal over and with their rivalry more friendly, Sonic asked Jet if the Rogues were leaving, to which Jet agreed on, since there were more treasure out there to find. Sonic then promised Jet that he would be ready to race him the next time they met, and the teams parted ways until they would meet again. (NOTE: Despite the intentions of the scene Sonic causing Amy to be blown away then lacking concern afterwards is supposed to be viewed as humorous, it is done at the expense of betraying Sonic's nature to be worried of his friends' safety. This is the first and only game he directly caused endangerment to an ally while attempting to save them, which contradicts him being cautious and aware of Amy's predicament such as in Sonic Adventure 2.)

Sonic Riders: Zero Gravity
In Sonic Riders: Zero Gravity, a few months after the EX World Grand Prix, Sonic was driving with Tails and Knuckles through Monopole, fumbling with a mysterious meteorite Tails had found the other night. On their way to Megalo Station, while Sonic was looking thoughtfully at the stone, he and the others were attacked by SCR-HD and a group of SCR-GP, a part of a currently global robot rampage who were after the meteorite. In the insuring chase, the group crashed and fell out from 300 stories high. As Sonic nearly fell to his death, he was saved when the meteorite activated, which Sonic discovered could manipulate gravity.

After joining up with his friends, Sonic and the gang tried to hide from the robots. While hiding, Sonic was taken by surprise when Amy snuck up on him. Sonic asked Amy what she was doing here, and learned that she was being chased by the robots because she had a meteorite similar to Sonic’s. Sonic then decided to head to creator of the robots, MeteorTech, to get some answers. Once at MeteoTech, Sonic and the gang were discovered by security, but then the Babylon Rogues arrived, and Jet repelled the security robots with another meteorite. Jet revealed he was after the meteorites, called the Ark of the Cosmos, and that he wanted to challenge Sonic to a race. Sonic was initially eager to face Jet’s challenge, but decided to postpone it as the alarm sounded and more robots showed up.

As Sonic raced Jet to the control room, he demonstrated to him that he could use the Arks of the Cosmos too. When they got to the control room, Sonic and the others were surprised to find Dr. Eggman, who was the owner of MeteoTech. Sonic immediately suspected that Eggman was behind the robot rampage, but he claimed that he had no part in it. However, once Eggman recognized the Ark of the Cosmos on Sonic’s wrist, Sonic saw that he was holding something back and insisted that he told them everything. Eggman revealed that MeteoTech’s mother computer was powered by one of the Arks of the Cosmos and that the robot leader, SCR-HD, which also happened to have an Ark of the Cosmos, sought them out for reasons unknown. The group then noticed that Amy was gone, and saw on the computer screen that she was being chased by SCR-HD and Storm, and Sonic headed out with Tails and Knuckles to save her.

Once arriving there, Sonic, Knuckles and Tails found Amy unharmed, and learned that SCR-HD had suddenly blown up and that Storm had taken its Ark of the Cosmos. Despite the leader being disabled, Tails deduced that to stop the robots, they had to remove the Ark of the Cosmos in MeteoTech’s mother computer. As the group tried to figure out where the mother computer could be, Amy remembered that Storm had mentioned Gigan Rocks, which held information about the Ark of the Cosmos. Though Knuckles warned that no one had returned alive from Gigan Rocks, Sonic and the others headed there to check it out.

Once they got to Gigan Rocks, the group learned from the ruins that the Arks of the Cosmos were power units for an ancient spaceship, which Sonic understood was Babylon Garden. The group then saw the Babylon Rogues chase after Eggman above them, and learned from both that and the ruins the location of Eggman’s Ark of the Cosmos and MeteoTech’s mother computer. When Sonic and his friends got to this location, they found the Crimson Tower and the Babylon Rogues, who revealed that Eggman had stolen their Arks of the Cosmos. Hearing Tails concluded that Eggman planned to use them to control all the world's robots, Sonic understood that this was Eggman's newest plan to conquer the world. Sonic was about to head out, but Jet intercepted him and demanded the race Sonic had postponed and Sonic gladly agreed to it. Jet then posed the challenge that whoever reached Eggman first got all the Arks of the Cosmos and the title of the fastest in the universe, and Sonic agreed to the terms.

The race eventually came to a draw, as both Sonic and Jet stopped Eggman at the same time, and brought an end to the robot rampage. After Babylon Garden had revealed itself due to all Arks of the Cosmos being present, Sonic gave his Arks of the Cosmos to Jet as he no longer needed them and took his leave with his friends. Jet however, accused Sonic for running away, since their race did not have a winner, but Sonic told him that they would settle the score at the next World Grand Prix. Just as Sonic and his friends took their leave, SCR-HD suddenly appeared and took all five Arks of the Cosmos to Babylon Garden. This resulted in Babylon Garden transforming into Astral Babylon and to form a black hole that threatened to consume the planet. Sonic went with Tails, Knuckles and the Babylon Rogues behind him, to Astral Babylon to disconnect the ship's engine. There, they faced Master Core: ABIS, who had merged with the black hole. However, by using its own power against it, Sonic and the others stopped Master Core: ABIS and saved the world.

With the world safe, Sonic, Knuckles, Tails and Amy later returned to Monopole, where they learned from Tails that the Arks of the Cosmos had a program which caused the robots to go amok and to collect them when they were hit by their influence. Sonic then heard Jet calling out his name and saw him fly by, and Sonic saw that he challenged him to a new race. Sonic enthusiastically accepted this challenge and raced Jet throughout the city.

Sonic Free Riders
In Sonic Free Riders, Sonic and the rest of Team Sonic entered the newest World Grand Prix, which was once again hosted by Dr. Eggman (under the alias as King Doc) as Team Heroes. Sonic and the team however, simply participated for the sake of the competition and the chance to get the title of world's fastest team, rather than the large cash price. When they introduced themselves to the viewers of the races, Sonic expressed his excitement and readiness to compete in the tournament. As Tails thought that the races seemed fishy, Sonic expected that Eggman was planning something and said that he was ready to take the doctor on anytime.

In their first race, Team Heroes saw that their first opponents were Team Rose, and Sonic was openly disappointed and confident that they could beat them. As their team won one challenge after another, Sonic was berated by Amy for not going easy on her, but Sonic insisted on taking this competition seriously. Eventually, Team Heroes beat Team Rose, but Amy demanded a date with Sonic to make it up for him beating her, though Sonic wondered why he owed her a date for winning.

For their next race, Sonic and Team Heroes went up against Team Dark. During the race, Knuckles suspected Team Dark’s member, E-10000B for foul play, but Sonic thought that he was just imaging it.

Sonic and the team eventually beat Team Dark and advanced to the finals, where they met Team Babylon. Sonic, however, was not surprised that Jet and his team had made it to the finals. In the final race between the teams, Sonic squared off against Jet and beat him, seemingly securing his team's victory. After Sonic gave his comments on how easy it was to win the race, however, he learned that Jet had mechanical troubles during the race, and he called for a rematch. Jet questioned Sonic why he would risk his first victory, but Sonic assured him open-heartedly that they deserved a rematch. Jet accepted Sonic's offer, though he warned him that he would regret it, but Sonic remained as confident as ever. Sonic and Jet them faced each other in a on-on-one race, where Sonic emerged victorious. After the race, Sonic was reached for comments by Omochao, and told him he felt incredible upon his victory. Wondering about how Jet took their defeat, Sonic heard from Omochao that Team Babylon was about to leave, but before they could, Sonic thanked Jet for the race and told him that he looked forward to their future rematch.

As the tournament progressed, Team Heroes had their own fair share of losses, but Sonic continuously displayed good sportsmanship. At the end of the tournament, all teams had an equal amount of victories and losses, and Sonic and the other teams came to the awards ceremony to collect their prize, but Eggman (as King Doc) made them have a final race against his ultimate Gear-Jockey robot. Sonic told Eggman to drop the act, but Eggman made them race anyway and Sonic sensed something was up.

After the race, Eggman dropped his disguise and revealed that he used the World Grand Prix to get the riders' racing data with his E-10000 robots to create the ultimate Extreme Gear which he could use for his own agenda, but Sonic thought that his plan was just lame. In retaliation, Eggman challenged Sonic and the others to a race, but lost. As he noticed E-10000B was acting funny, Sonic saw Metal Sonic emerging from it, and heard that Metal Sonic had stolen Eggman’s data and given the doctor fake data. Sonic then noticed that Metal Sonic was challenging him to a one-on-one race and, despite being told that Metal Sonic could not be beaten on a Extreme Gear, Sonic gladly accepted the challenge.

Eventually, Sonic was victorious, and Metal Sonic ran away afterwards. As Eggman cursed being tricked, Sonic mocked Eggman for ruining his own plan and that it made his job as a hero easier. The other teams then began to leave as well, but Sonic told them that they had a great time at the World Grand Prix nonetheless.

Sonic the Hedgehog (2006)
The 2006 game Sonic the Hedgehog, which celebrated the 15th anniversary of the series, featured a new rival to Sonic, Silver the Hedgehog, who possesses powerful psychic abilities.

In this game, Sonic visited Soleanna, having learned Dr. Eggman would attack it. Once he got there, Sonic arrived in the nick of time to save their monarch, Princess Elise, from Eggman, who had come after the Flames of Disaster, known as Iblis, to help him control time and rule the world, which was sealed inside Elise. Over the course of their adventures, the two of them would come to develop a strong relationship.

After destroying Eggman's initial forces, Sonic ran off with Elise to escape Eggman. While escaping, Elise asked Sonic why he helped her, but he just said he had "no special reason". Soon after, Sonic ran into some more robots, forcing him to put Elise down while he destroyed them. This proved however to be a distraction, and Eggman kidnapped Elise and escaped, but not before Sonic received her Chaos Emerald. With the Chaos Emerald in hand, Sonic promised Elise that he would save her. The next day, Sonic met up with Tails and let him help him in his mission to save Elise. The duo managed to locate Eggman’s ship, the Egg Carrier, at Wave Ocean and tried to catch it, but failed.

After returning to the city, Sonic and Tails learned that Eggman had been seen in Dusty Desert. The duo traveled to his base there, where they found Elise, who was happy to see Sonic. Their reunion was cut short, however, as Eggman appeared and tried to stop them with the Egg Cerberus. After Sonic managed to defeat it, the group tried to escape, but were pursued by Eggman's forces. Fortunately, Sonic and Elise managed to escape them by letting Tails create a diversion. As they escaped, Sonic took Elise over some plains, where he was thanked by Elise for his help. As she saw that Sonic was hurt, he told her it was nothing, but was nevertheless treated by her. While treating him, Elise apologized for Sonic’s injury, but Sonic merely told her to smile, which was all the reward he needed. Sonic was then filled in on the history of the Flames of Disaster and Solaris (the sun god honored by Soleanna) by Elise, who worried what could happen if Eggman unleashed Solaris’ wrath. Trying to cheer Elise up, Sonic grabbed her hand and made her run with him through the plains. After cheering her up from their run, Sonic gave Elise some advice to go by and took her back to Soleanna.

As Sonic and Elise returned to the town, however, Sonic was attacked by Silver the Hedgehog, who called him the "Iblis Trigger" and claimed that Sonic’s actions would destroy his world. Sonic initially had the upper hand in their fight, but Silver managed to catch Sonic off-guard and psychokinetically threw him into a building, incapacitating him. While lying dazed on the ground, Sonic saw Eggman kidnapping Elise again and tried to run after the escaping Eggman, but Silver kept him from leaving. Luckily, Sonic was saved by Amy, who prevented Silver from killing him. After thanking Amy for saving him, Sonic resumed his chase after Eggman.

Sonic later met up with Tails and Knuckles, who gave him a holographic message from Eggman. The message demanded Sonic’s Chaos Emerald in exchange for Elise. While Tails and Knuckles were positive it was a trap, Sonic decided to go anyway, intending to "thank" Eggman for telling him of Elise’s whereabouts. After arriving at Eggman's base in White Acropolis, Sonic gave Eggman the Chaos Emerald, but was tricked and sent to the future by Eggman's newest machine along with Tails and Knuckles. Arriving in an apocalyptic future, the group met Shadow and Rouge, who had been sent there by Mephiles (Solaris’ mind and conscience). After finding out from Shadow and Rouge where they were and how to return home, Sonic understood that they planned to use Chaos Control to create a space-time rift, and saw that the circumstances required them to work together to find the Chaos Emeralds needed for the travel.

While searching for the Chaos Emeralds, Sonic, Tails and Knuckles saw Silver and Blaze talking with Mephiles, who told them that Sonic was responsible for the devastation of this future and took them back in time to kill Sonic. After they left, Sonic and the others learned from their database that Elise would die in the Egg Carrier's crash landing three days after he met her, leaving Sonic more determined than ever to save her.

Sonic and the gang later met up with Rouge and Shadow after learning the location of a Chaos Emerald in Flame Core. After heading into the innermost recesses of the region, the group a Chaos Emerald when they attacked by Iblis, but Sonic and Shadow managed to defeat it. With two Chaos Emeralds in their possession, Sonic and Shadow performed Chaos Control, thus creating a rift in time, and Sonic, Tails and Knuckles returned to the present. Though Shadow and Rouge did not return with them, Sonic assured his friends that they could take care of themselves.

With little time to spare, Sonic and the others discovered Elise's whereabout. Sonic then ran off on his own and saved Elise from Eggman's train, but he was attacked by Silver again. As he was caught by Silver, Sonic saw Elise being kidnapped by Eggman, who escaped once more. Fortunately, Shadow arrived and fought Silver, allowing Sonic to pursue Eggman. As Sonic gave chase, he managed to rescued Elise from a lethal fall, before confronting and destroying the Egg Genesis. As they escaped Eggman’s forces, Sonic took Elise to a beautiful location with Cherry Blossom trees and a lake to cheer her up. There, Sonic told Elise that he would leave once he defeated Eggman, but Elise nevertheless thanked Sonic for this adventure, and Sonic promised her that he would remember this place. While Elise nearly cried because Sonic had to leave, he comforted her and told her to keep smiling.

Sonic returned Elise to the castle soon after, but unfortunately, Eggman kidnapped Elise once again after he threatened to destroy Soleanna. Sonic soon caught wind of the news and ran off to save Elise again. On his way, Sonic was attacked by Eggman's robots, but was assisted by Silver who was now willing to help Sonic save Elise. Though initially confused, Sonic gladly accepted his help. Unfortunately, Sonic was too late and saw Eggman’s ship crash and explode with Elise inside as predicted. As Sonic despaired at the loss of Elise, Silver came up with a plan to send Sonic back in time to save Elise. Using Chaos Control and two Chaos Emeralds, Sonic and Silver created a space-time rift, but before he left, Sonic told Silver that he would change his future too by saving Elise, and thanked Silver for his help. Sonic managed to arrive at the day before the crash, and bordered the Egg Carrier as it launched. He then went and defeated Eggman in the Egg Wyvern onboard the ship and narrowly escaped the exploding Egg Carrier with Elise.

As Sonic and Elise returned to the city, Sonic was distracted by Mephiles' Chaos Emerald. Mephiles himself then appeared behind Sonic, who impaled him through the back with an energy beam, killing him instantly. As Elise realized that Sonic was dead, she broke into tears, thus releasing Iblis from within her. Mephiles then merged with Iblis and Solaris was reborn. Solaris then proceeded to create a time rift from where he could consume time itself, creating a spatial distortion that transported Sonic's body and Elise to the End of the World. There, the game's main cast arrive as well, only to see Sonic’s dead body in Elise’s arms, each showing sadness at his death. As the group learned about Solaris’ intentions, Silver came up with a plan to destroy Solaris, but Shadow stated that with Sonic gone, they stood no chance of defeating Solaris.

It turned out, however, that Sonic’s soul had yet to pass on at this point and Elise sensed his presence in the wind. Realizing that it was not too late, Tails, E-123 Omega, Knuckles, Silver, Rouge, Amy, and Shadow gathered all the Chaos Emeralds to restore Sonic to life, and with Elise's kiss, Sonic was revived as Super Sonic, who thanked her for bringing him back. He proceeded to turn Shadow and Silver into Super Shadow and Super Silver and they fought Solaris. After they defeated him, Sonic and Elise were sent back in time to where Solaris was just a flame in a candle. If Elise blew out the candle it would destroy Solaris forever, but with Solaris gone, the events of the adventure would be negated and Elise would never meet Sonic. Elise initially chose Sonic over the world, but Sonic told Elise to smile and to accept things as they were, and she extinguished the candle. Time was reverted, but Sonic still traveled to Soleanna. There, Sonic saw Elise coming, and ran by her so fast that the wind created from his speed caused Elise's memory to momentarily trigger. As the festival proceeded, Sonic watched happily and satisfied as one of Elise's feathers floated skyward, hinting that he remembered this adventure. (NOTE: A noticeable difference of Sonic's personality in this game is while his kind, helpful, and caring aspects are kept, his playful and feisty nature is missing.)

Sonic Rivals
In Sonic Rivals, the mysterious Onyx Island had appeared out of nowhere at sea. Once he heard these news, Sonic headed out with Tails to investigate this island, as Sonic had a hunch it was another of Dr. Eggman's schemes. As soon as they arrived, Sonic spotted who he believed to be Dr. Eggman, but was really Dr. Eggman Nega disguised as Dr. Eggman (Sonic however, does not realize this throughout the game). Wasting no time, Sonic confronted the doctor, but Eggman Nega pulled out a card, which left Sonic shocked to see depicted Amy Rose. Eggman Nega explained he had turned Amy into a card with a special camera, but Sonic did not believe the doctor's story. However, as Sonic heard Tails stating his opinion, a flash from Eggman Nega's camera blinded him, and when he regained his sight, Tails was gone. Sonic asked Eggman Nega what he had done, and the doctor revealed that he now not only had turned Amy, but also Tails, into cards. At the same time, Knuckles appeared, believing Eggman Nega had stolen the Master Emerald. As Eggman Nega claimed himself gulty of the theft of the Master Emerald by turning it into a card as well, the doctor told them that they had to catch him first to get the cards back and escaped, and Sonic raced Knuckles to see who got to face Eggman Nega first.

After the race, the two found Eggman Nega and they teamed up to fend off one of his creations, but Eggman Nega escaped. As Sonic gave chase to him, however, he ran into Silver for the first time (since the events of Sonic the Hedgehog (2006) were negated), who had come to bring Eggman Nega back to the future. As Silver insisted on getting to Eggman Nega first, Sonic gladly accepted the challenge, and the two of them raced after Eggman Nega. As Sonic reached Eggman Nega, he demanded the cards back, but Silver still insisted on going first. Sonic started to get annoyed by Silver’s attitude and it broke down to a fight between them and Eggman Nega's Egg Falcon.

Despite defeating the Egg Falcon, Sonic and Silver continued to fight. As Sonic gained the upper hand in their fight, however, Silver teleported him to another location. Surprised, Sonic started to look around and found Shadow. He saw that Shadow was after Eggman Nega as well and Sonic challenged him to a race to see who got to Eggman Nega first. Sonic eventually outraced Shadow, much to his own pride, and found Eggman Nega, and demanded to know what he was up to. Eggman Nega however, retaliated by unleashing Metal Sonic on Sonic, who was surprised to see his old rival again. After Sonic defeated Metal Sonic, he thought about Eggman Nega’s plan, but then ran into Silver again, who was surprised to see him so soon. Sonic then told Silver that he would share his information with Silver, if he beat him in a race to Eggman Nega, and the pair gave chase to the doctor again.

Sonic and Silver eventually cornered Eggman Nega and Sonic demanded Tails’ card back, but Eggman Nega still intended to defeat Sonic. Sonic however, told him that he would never win, and he and Silver began fighting Eggman Nega’s Egg Lynx. Eventually they defeated it and Sonic reclaimed Tails’ card, while Eggman Nega escaped. Sonic freed Tails from his card and assured him that he would stop Eggman Nega, but then Knuckles reappeared and Sonic was challenge by him to race to see who got to Eggman Nega first.

Sonic eventually reached Eggman Nega first and told him that he would always find him, before he faced both the Egg Kong and an upgraded Metal Sonic, but still won. Frustrated at his constant defeats, Eggman Nega told Sonic that he now planned to turn the world into a card that he could control as he wished and escaped, much to Sonic’s frustration. Tails however, appeared in the Tornado and Sonic was able to travel to Eggman Nega’s base. As Sonic ventured to and through Eggman Nega’s base, Knuckles, Shadow and Silver also appeared. With each meeting, the rivals put aside their differences and teamed up with one another to help stop Eggman Nega, and Sonic accepted each of their help.

At the center of the base, Sonic and the others found a large spaceship with Eggman Nega’s special camera equipped on that he planned to use to turn the entire world into a card. Sonic then noticed that Eggman Nega planned to fuel the device with Amy’s card (which Sonic had forgotten about) and some other cards he had taken, but the four rivals headed into battle and destroyed the spaceship as it took off, thus foiling Eggman Nega’s plan for good.

After the battle, Sonic freed Amy from her card, who believed this meant that Sonic and Amy were to live happily together. Sonic on the other hand, came up with an excuse by telling her that he had to find the remaining captives in Eggman Nega’s cards and immediately ran off. (NOTE: This is the third game to compromise a trait of Sonic's personality in favor fulfilling another element to the "running gag" dynamic between himself and Amy. He takes initiative of acquiring Tails' card back but to forget hers until later displays favoritism who he saves and who he cares for; a trait unlike him.)

Sonic Rivals 2
In Sonic Rivals 2, while on his own, Sonic received a call from Tails, telling him to meet him on an island. Once arriving there, Sonic heard from Tails that a group of Chao have gone missing. After he also heard from Tails that he suspected Eggman, who had been seen on the island, to be behind this, Sonic teamed up with Tails to find Eggman and get some answers. As they were about to head out however, Sonic saw Knuckles with Rouge and teased Knuckles by asking them if they were on a date. While annoyed, Knuckles asked if he had seen Dr. Eggman, and Sonic asked why. Knuckles then reluctantly answered that the Master Emerald had been stolen, but Sonic was not surprised to hear it. Sonic, however, insisted on finding Dr. Eggman first, and the two squared off in a race and later a fight to find him.

Sonic and the others eventually found Dr. Eggman, who really was Eggman Nega masquerading as Dr. Eggman once more (and again, Sonic does not realize this throughout the game). Sonic demanded to know what he had done with the missing Chao, but Eggman Nega claimed that he had nothing to do with it. Sonic however did not buy it, and Eggman Nega attacked Sonic and the others in his Egg Liner. After the fight, Sonic and Tails followed the escaping Eggman Nega through to Sunset Forest Zone. As they lost the doctor's trail, the duo found a book page dropped by Eggman Nega mentioning a creature called the Ifrit. Soon after, Sonic ran into Silver and guessed that he were after Eggman Nega too. Seeing that Silver was determined as ever not let him get in his way, Sonic challenged Silver to a number of fights to see who got to face Eggman Nega first.

Sonic and Tails eventually found Eggman Nega with Silver and Espio, and he questioned the doctor why he was running away if he was not involved with the missing Chao, but Eggman Nega defiantly attacked them in his Egg Dealer. After the fight, Sonic and Tails followed Eggman Nega to Neon Palace Zone. As they lost track of him, Sonic and Tails found more dropped book pages that described the Ifrit's powers, which worried Sonic. While in the city, Sonic briefly met Shadow, who was with Metal Sonic. Suspicious at why Metal Sonic was involved, Sonic and Tails decided to follow the pair, with Sonic following Shadow. After catching up with Shadow, Sonic began questioning Shadow, but he refused to give an answer, and they began to fight. After the fight, Sonic and Shadow found Eggman Nega who proceeded to attack them in his Egg Dealer, but the group managed to defeat the contraption.

Sonic and Tails afterwards tracked Eggman Nega to Frontier Canyon Zone, where they found more dropped book pages on the Ifrit, and Sonic began to suspect it had something to do with Eggman Nega's plans. In the wasteland, the duo met Knuckles and Rouge again, who revealed they were searching for the Master Emerald using an Emerald Detector, but they needed Rings to fuel it, and Sonic volunteered himself and Tails to search for some. After Sonic had gathered enough Rings however, Espio appeared and took them, as he and Silver needed them to find Eggman Nega, but Sonic pursued him. Afterwards, Sonic ran into Eggman Nega again and demanded to know his plan, with the doctor saying that he had to beat his Egg Bull for that. Despite the untimely interference of Silver and Espio, Sonic and Tails managed to win. Sonic told Eggman Nega to keep his promise and the doctor revealed his plan to release the Ifrit into the world from a portal within a haunted mansion and Sonic and Tails headed there to stop the Ifrit.

Once arriving at the mansion, Sonic and Tails split up. While searching, Sonic ran into a shape-shifting ghost and engaged it victoriously in battle. Once reunited with Tails, they found Eggman Nega with their ghost counterparts, but Sonic thought that 'Eggman' was also possessed by a ghost. After fighting Eggman Nega in his Egg Phantom, Tails found the missing Chao inside a secret room, which Eggman Nega had planned to feed to the Ifrit to make it invincible, and Sonic told Tails to bring the Chao to safety while he searched for Eggman Nega.

Sonic and Tails eventually found the portal to the Ifrit's dimension, which was about to close (due to Shadow’s and Metal Sonic’s actions) and they headed inside to find Eggman Nega before it was too late. As Sonic and Tails ventured through the Ifrit’s dimension, they faced the Ifrit itself, who took control of Tails. Seeing no choice, Sonic faced both Tails and the Ifrit to stop it from destroying the world. Despite Sonic occasionally falling prey to the creature's mind control himself, the two friends managed to defeat the Ifrit, thus preventing it from leaving its world, and escaped before the portal closed. With the Ifrit stopped, the world safe and the Chao rescued, Sonic saw no reason to find Eggman Nega so he and Tails headed to the Chao Garden to get some rest.

Sonic and the Secret Rings
In 2007, Sonic and the Secret Rings was released. After waking up from his nap, Sonic encountered the genie of the ring, Shahra from the world of the Arabian Nights. She revealed that an evil genie called Erazor Djinn was absorbing her world, the very power of the book itself and if he was not stopped, he would enter Sonic's world too. She also revealed that Sonic was the "Legendary Blue Hedgehog" foretold in legend, who could stop him. More than willing to help, Sonic agreed to help Shahra and she lead him into her world. While entering the Arabian Nights, Sonic encountered Erazor, who demanded that Shahra gathered the seven World Rings, but she refused. Trying to punish her with a curse, Sonic took the blow for Shahra and was shot in the chest with a flaming arrow. Erazor then demanded before he left that Sonic gathered all the World Rings for him before the arrow burned out, or he would die. Sonic then head into the Arabian Nights, with Shahra at his side, intending to stop Erazor before it was too late.

On his adventures through the Arabian Nights, while stopping Erazor's plans along the way, Sonic collected all the World Rings and learned about a past relationship between Shahra and the Erazor Djinn. With the help of King Solomon, Sonic eventually faced the Erazor Djinn in his stronghold and defeated him, who then retreated under a sealed door in there. Using the Seven World Rings, Sonic opened it and found Erazor waiting for him. Sonic then told Erazor to remove the curse, but he did not keep his word. Instead, Erazor took the World Rings by manipulating Shahra and tried to sacrifice Sonic to gain control of the rings, but Shahra saved Sonic at the cost of her own life. Erazor then used the seven World Rings, hoping to gain total control over the Arabian Nights, but ended up transforming into the incomplete Alf-Layla-wa-Layla. Three of the World Rings was then absorbed by Sonic who transforms into Darkspine Sonic, which broke the curse, and he defeated Alf-Layla-wa-Layla.

With Erazor defeated, Sonic decided to use Erazor's lamp, given to him by Shahra earlier, to make him grant three wishes: Revive Shahra, restore the Arabian Nights and seal Erazor himself away in his lamp forever. Having no choice, Erazor granted all of Sonic's wishes and the Arabian Nights were saved. Though Shahra cried over the fate of Erazor, Sonic wished for a mountain of handkerchiefs, allowing her to cry as much as she needed to.

Sonic and the Black Knight
The second installment in the Sonic Storybook series, Sonic and the Black Knight, came out in 2009. One day, while apparently enjoying some chili dogs, Sonic was waiting for Amy, as he had somehow been talked into going on a date with her, though it was expected to be a stressful experience. Suddenly, however, Sonic was abruptly called into the world of Camelot by Merlina the Wizard, in order to defeat King Arthur, who had become the evil and tyrannical Black Knight after being corrupted by the power of the Scabbard of Excalibur, which made him immortal. After a not-so-graceful arrival, which involved Sonic falling from a portal in the sky and hitting the ground face-first, he soon came to realize that he was in unknown lands. Merlina then appeared before Sonic, revealing herself as the one responsible for his arrival. After taking a look on the approaching King Arthur, however, Sonic understood the situation, and quickly dispatched King Arthur's Knights of the Underworld. Sonic then tried to take on Arthur next, but he was restrained by Merlina, who teleported Sonic and herself away from the battle field.

After retreating from King Arthur, Sonic was filled in by Merlina on the kingdom's situation. Merlina then lead Sonic to the Sacred Sword Caliburn, a sentient sword who would become Sonic's teacher in knighthood, hoping to give Sonic a better fighting chance. Sonic's relationship with Caliburn came off to a rocky start, however, due to their conflicting personalities.

After another brief confrontation with King Arthur (who left because he did not think Sonic was a threat), Sonic and Caliburn sought out Nimue, Lady of the Lake who knew how to stop the Scabbard of Excalibur. During their search, Sonic came across Sir Lancelot who was sent to kill him, but Sonic luckily managed to defeat him and took his sacred sword Arondight.

Sonic and Caliburn eventually found Nimue, who Sonic was initially freaked out by (due to her striking resemblence to Amy). Nimue told Sonic, however, that she would only reveal the secrets about the Scabbard to him, if he passed a test of true knighthood, and tasked him to free King Arthur's innocent prisoners, offer help to people in need and defeat King Arthur's minions within three days time. Confident, Sonic told the concerned Caliburn that he would be a knight before long.

Sonic then headed out with Caliburn to complete the tasks. As they were working on completing the tasks however, Sonic met a young villager whose family and fellow villagers were kidnapped by a dragon. After he learned from the child where to find the dragon, Sonic decided to help the child. Caliburn, however protested against this as they would risk running out of time, but Sonic, though aware of the risks, said that he follows his own rules and took off. On their way to the dragon, Sonic encountered Sir Gawain, who had come to kill him, and fought him in battle. Sonic eventually managed to beat Gawain, and prevented him from commiting suicide as the echidna felt he had failed his king. Sonic then asked him if there was more to being a knight than serving a king, before leaving with Gawain's Galatine to save the villagers.

Sonic eventually managed to save the villagers, though at the cost of running out of his three day time limit. When Sonic met the child from earlier, however, she revealed herself to be Nimue in disguise, and told him that by helping her, Sonic had passed her test and proven himself as a true knight. Keeping her end of the bargain, Sonic learned from Nimue that he had to collect all of the Sacred Swords and that their united power would negate the Scabbard's power. Having already gathered two of them from his fights with the Knights of the Round Table along the way, Sonic went to get the last one from Sir Percival. After not only defeating Percival, but also saving her life, Sonic finally gained Caliburn's respect and was titled "Sir Sonic, Knight of the Wind".

With all four Sacred Swords, Sonic faced King Arthur and defeated him, but was left confused as he saw him vanish as one of his minions (in a puff of smoke). As Sonic returned with the Scabbard of Excalibur to Merlina, she revealed that she had used Sonic all along so that she could use the scabbard for herself to prevent the grim fate that awaited the kingdom, though at the cost of many lives.

Sonic regrouped with the Knights of the Round Table after Merlina's initial assault, and managed to unite them against Merlina. With Nimue's advice, Sonic and the Knights of the Round Table tried to contain Merlina's influence with a magical barrier. Once the barrier was set up, Sonic went and faced Merlina himself. In the heart of her castle, Sonic confronted Merlina, now the Dark Queen, who told him the fate that awaited the kingom to make him understand her sadness. Sonic, however, turned a deaf ear to Merlina and tried to attack her, but received a massive beating from her and got Caliburn cut in half. Nevertheless, Sonic refused to give up, which brought forth the power of all the Sacred Swords, transforming himself into Excalibur Sonic and Caliburn into Excalibur.

Together, Sonic and Caliburn defeated Merlina and Sonic convinced Merlina to let go of her driving sadness and to live her life to the fullest, despite her world's fate. As the Knights of the Round Table thought about disbanding now that they do not have a king, Caliburn revealed to them that he chooses the king, which meant that Sonic was the true King Arthur of this world, much to Sonic's surprise. Depite this new title, Sonic returned home, where he tried to explain his adventure to Amy, but she did not believe his story and instead claimed that it was just an excuse for forgetting their date they promised, leaving Sonic to run away from an enraged Amy and her Piko Piko Hammer.

Sonic Chronicles: The Dark Brotherhood
In the beginning of Sonic Chronicles: The Dark Brotherhood, Sonic, Tails, Knuckles and Amy were facing Dr. Eggman onboard the Egg Carrier. Together, they succeeded in making the Egg Carrier crash into Metropolis and Eggman was presumed dead.

With Eggman and his forces gone and no need for him to be a hero anymore, Sonic went on a long vacation alone, spending his time exploring the world. Some time later, however, Sonic received a call from Tails who said that the Chaos Emeralds had been stolen and that Knuckles had been kidnapped by a group dubbed the Marauders. Tails told Sonic that they needed his help to save Knuckles and Sonic gladly agreed to help. As he made his way through Green Hill Zone, Sonic was joined by Amy, and the two of them fought off a Marauder Scout. Sonic then made his way to Tails' Lab, where he and his friends began their search for Knuckles.

With some help from G.U.N., Sonic and his friends managed to find four Communicators that pinpointed the Maurauders' hideout in Mystic Ruins. There, Sonic and the team found Knuckles as he was trying to escape. When the team tried to get to Angel Island to protect the Master Emerald from the Marauders, however, they discovered that Angel Island had been hijacked. Sonic suspected that Eggman was behind this, due to the Marauders using Eggman’s robots, and the group began looking for the doctor using Tails' Eggman Detector. After finding five Eggman Devices, Tails made a Pattern Generator that the team used to unlock Eggman's hideout in Green Hill Zone. Upon finding Eggman there however, the doctor claimed that he was against the Marauders as well, and that he had also been reformed. Eggman also said that he was willing help Sonic and the others in the fight against the Marauders by leading them into Metropolis where the real hijackers, the Marauders, had drawn Angel Island to with the Chaos Emeralds. While Sonic was distrusting of Eggman's motives, he let the doctor join.

On the way there, through Blue Ridge Zone, the team came across Shadow. Not interested in telling them what he was doing, Shadow fought Sonic's team and tried to escape, but Sonic caught up with Shadow and defeated him. After the fight, Shadow revealed that he was looking for Omega as he thought the Marauders had caught him and Sonic convinced Shadow to join them as they had a common enemy.

Later, Sonic and the others met one of the soldiers from the Marauders, called Shade, who revealed that she and the Marauders were a group of echidnas called the Nocturnus Clan, exiled to the Twilight Cage in ancient times. Despite defeating her, Shade blocked their way to Metropolis, but Sonic and the others managed to find a way around it. In the meanwhile, Sonic tried to support Knuckles, who had found others of his kind, but was forced to fight them. Once in Metropolis, they divided into two teams with Sonic and Knuckles going to Angel Island to prevent the Nocturnus Clan from stealing the Master Emerald, while Tails and Eggman prepared a weapon against the Nocturnus Clan.

By hijacking on one of the Nocturnus Clan's airships and with some help from Tails' team, Sonic, Knuckles and their group made it to Angel Island. There, the group met the Nocturnus Clan’s leader, Imperator Pir'Oth Ix, who sought to rule the world, which shocked Shade, who just wanted to leave the Twilight Cage. Ix's then unleashed his soldiers who overwhelmed them, but Sonic continued to stand his ground until Tails and Eggman had the weapon ready. As they were wearing down, Tails and Eggman deployed the weapon, which dispatched the soldiers, thus saving Sonic and his group. With his full team supporting him, Sonic fought Ix, but despite their best efforts, they were unable to stop Ix from stealing the Master Emerald. Ix then used the Master Emerald to create a wormhole into Sonic’s dimension so that the Nocturnus Clan could conquer it, and Angel Island fell from the sky. With the Nocturnus Clan possessing all the Emeralds, some of the team began to despair, but Sonic refused to give up and assured them that they would stop Ix. The team then came up with the plan of going after Ix into the Twilight Cage and reclaim the emeralds, and Shade joined Sonic’s team to stop Ix’s plan.

After Sonic and his team restored the Power grid and retrieved the Dimensional Buffer, Tails and Eggman constructed the Cyclone. Sonic and the others then used the vessel to enter the Twilight Cage, while Eggman stayed behind to watch the entrance portal. Once inside the Twilight Cage, the team crash-landed on the Kron Colony. There, Sonic and the team managed to free the Kron people from the Nocturnus Clan, gained the Krons' support and reclaimed a Chaos Emerald. Later, the team arrived at the N'rrgal Colony, where the N'rrgal Queen forced Sonic and his team to retrieve the Chaos Emerald from the N'rrgals' enemies, the Zoah. On the Zoah Colony, Sonic defeated their leader General Raxos and not only got their Chaos Emerald, but also gained the Zoah as alies. The team then returned to the N'rrgal Colony and received their Chaos Emerald as thanks and got their alliance as well. On Voxai Colony Alpha and Voxai Colony Beta, the team was pitted against the powermad Overmind, but thanks to a psychically treated Chaos Emerald, Sonic resisted their mind-control. Together, the team then defeated the Overmind, thus gaining two Chaos Emeralds. Along the way, Sonic also offered Shade to live on Earth once it was over, which she accepted.

As the team prepared to invade Nocturne to find the last Emeralds, Sonic managed to unite the conflicting alien races in the battle against Ix, and with their help, Sonic and the others infiltrated Nocturne. Once there, they split into two teams, with Sonic and Tails leading their group and Knuckles and Shade leading the other, to find the last two emeralds, which was in the possession of Charyb and Scylla.

On their way to Charyb, Sonic and Tails helped Knuckles' group defeat some Gizoid Centurions. When Sonic and his group found Charyb, they tried to fight him, but because the battlefield was submerged in water, the Gizoid was invincible. Fortunately, Knuckles' group managed to drain the water there, allowing Sonic and his group to beat Charyb and reclaim the Chaos Emerald. After hearing that Knuckles' group had reclaimed their Chaos Emerald as well, Sonic and his group headed to Ix’s throne room to stop Ix. There, Sonic saw Knuckles talking to Ix and believed that he was going to betray them, but was proven wrong as Knuckles remained loyal to his duty and attacked Ix. After Knuckles’ fight, Sonic then stepped in and stalled Ix, while Knuckles got the Master Emerald back.

After the fight, Sonic told Ix it was over, but the echidna leader refused defeat and used Nocturne’s power to become Super Ix, but Sonic retaliated by using the seven Chaos Emeralds to become Super Sonic and defeated Ix for good. As a final act however, Ix started to close the wormhole out of the Twilight Cage, but Sonic and the others managed to get through it just in time. When they returned home however, Sonic and the others saw that much time had passed, thus allowing Eggman to rebuild his forces, which they faced upon exit from the Twilight Cage. (NOTE: Even though Sonic and Knuckles' relationship has always shown forms of disagreements and arguments, they overall maintain trust between each other. However, Sonic's suspicion of Knuckles is a plot driven that shows he in his words, "I knew it! He's going to betray us!" of Knuckles being underhanded rather his usual response of his friend's naivete of being manipulated.)

Sonic Unleashed
In Sonic Unleashed, the story begins after an untold series of adventures for Sonic, as he arrived at Dr. Eggman's massive fleet in space and began blasting through his forces, before he was confronted by Eggman in a powerful mech.

As Sonic was forced on the defensive, he was captured by Eggman, but Sonic retaliated by turning into Super Sonic and he destroyed Eggman's mech, and trashed his fleet as well, as he chased the escaping Eggman. As Super Sonic chased Eggman to a space station, he believed he had cornered Eggman. Sonic soon realized, however, that he had been lured into a trap and he ended up being caught in Eggman's Chaos Energy Cannon where Super Sonic had the Chaos Emeralds painfully removed from him, returning him to normal. With the Emeralds' power, Eggman fired the cannon at the planet, breaking it apart and awoke the ancient creature called Dark Gaia, in order to harness its power. In the process, a part of Dark Gaia's energy infected Sonic and turned him into a monster version of himself. As he was released from the trap, Sonic was rejected from the station by Eggman and fell plummeting towards the planet with the powerless Chaos Emeralds.

Moments before impact, however, Sonic was saved by a green light which broke his fall, but still left him crashing into the ground. After recovering, Sonic found an unconscious imp-like creature nearby. After he awoke, they introduced each other, but Sonic realized that the creature suffered from amnesia, as he could not remember anything. Believing that he caused his memory loss by falling on him, Sonic promised to help him recover his memories, much to the creature's delight. Dawn then broke and Sonic returned to normal, much to his own surprise.

The duo soon arrived at Apotos and Sonic decided to name his new friend Chip after an ice cream he had taken a liking to. After a day's fruitless search for someone who knew Chip, night fell and Sonic turned into his werehog form again, and he realized the nature of this transformation. They soon ran into Tails who was attacked by Dark Gaia's Minions, but Sonic saved him. As Tails recognized Sonic, even in his new form, Sonic explained his story to Tails, who suggested that they should talk to his friend Professor Pickle in Spagonia, who might know something about this, but they arrived only to hear that Eggman had kidnapped the professor for his knowledge about Dark Gaia.

Sonic, Tails and Chip tracked the professor down to Mazuri and they saved him from his prison in Eggman's base and reclaimed the stolen Gaia Manuscripts. They learned from the professor that Dark Gaia was the reason that the planet had broken apart, but that it had yet to be fully reborn due to its unnatural awakening. With this window of opportunity, Sonic was told by Professor Pickle that he could restore the planet and the Chaos Emeralds by placing the drained emeralds in the Gaia Temples across the world.

Sonic and Chip returned to Mazuri just in time to fight off Eggman and they located a Gaia Temple. Inside the temple, Sonic witnessed Chip's ability to activate the temple, and after placing a Chaos Emerald there, the emerald and a continent was restored. Hearing of his progress from Tails, Sonic saw this as a good opportunity to see the world.

When returning to Spagonia at night, Sonic encountered Amy, but was shocked to see that Amy did not recognized him as a werehog and became depressed as he thought that he was not same person anymore. He later found Amy caught in a group of people possesed by Dark Gaia, but with Chip's help, Sonic exorcised the people. After saving Amy, however, Sonic left before she could see him, but he eventually faced Amy with his condition.

Sonic and Chip continue their adventure across the world, healing it one piece at a time. At the time they reached the sixth temple, however, Sonic started to notice that Chip was acting scared. As the two of them restored the sixth continent, Sonic withnessed Chip regaining his memories inside the sixth temple. With his memory restored, Sonic learned that Chip's real name was Light Gaia and that he had been fighting Dark Gaia in a continuous cycle of destruction and restoration of the planet since the dawn of time. Sonic came to the conclusion that Chip was the reason he remained the same person, even when in werehog form, but Chip revealed that it was Sonic's own will and strong heart that prevented him from succumbing to the darkness inside him. After thanking Sonic for showing him the world and his help, Chip tried to leave to stop Dark Gaia on his own, but Sonic stopped him and said that he would help his friend despite these revelations, which Chip accepted.

Sonic and Chip then arrived in Eggmanland in order to find the last temple, which was located beneath it. As they placed the final emerald in the temple and the last continent moved back into place, Sonic (in his werehog form) and Chip believed it was now over, but were then suddenly attacked by Eggman in his Egg Dragoon, in order to finish Sonic for good. After Sonic defeated Eggman at the planet's core, Dark Gaia itself appeared and knocked Eggman into the distance, before engaging Sonic and Chip. As Sonic avoided Dark Gaia's attacks and stood eye to eye with the great beast, Sonic fell faint to the ground as Dark Gaia painfully sucked the last missing fragment of its power out of him, thus curing him of his werehog condition. All weak from the energy drain, Sonic told Chip to run, but Chip called upon the Gaia Temples to form the Gaia Colossus. Sonic soon after recovered from his exhaustion and together with Chip in the Gaia Colossus, they fought Dark Gaia.

During the fight however, Dark Gaia fully matured and became Perfect Dark Gaia and prepared to cast the world into darkness. Sonic was however determined not to let Perfect Dark Gaia succeed, and harnessed the Chaos Emeralds' full power and became Super Sonic once again. Together with Chip, the heroes slayed the terrifying monster, but Super Sonic was given a tough fight and he fell unconscious in his normal form after defeating the beast. He was then returned to the surface by Chip, as he got sealed inside the planet and returned to dormancy. After landing on the surface, Sonic found himself back where he met Chip and found his necklace, which he kept as a bracelet. As he heard Chip's final goodbye, Sonic paid his respect to his friend and ran off to look for new adventures, accompanied by Tails.

Episode I
Sonic returns in an episodic downloadable title called Sonic the Hedgehog 4 as the sole playable character; this game takes place after the events of Sonic & Knuckles and takes place before the events of Sonic Adventure. Unlike its chronological predecessor, Sonic still retains his green eyes and Homing Attack in it.

In Episode I, Sonic had just finished his adventure in Sonic & Knuckles and had managed to finally destroy the Death Egg. With this whole ordeal over, Sonic decided to take a much deserved break from his adventures. Sonic then parted with Tails and Knuckles for the time being, and ventured out on his own to explore new parts of the world. Sonic's break was cut short however, as Dr. Eggman revealed himself to be alive after their last encounter, and had returned to defeat Sonic for good with a new army of Badniks.

Sonic then began chasing and fighting Dr. Eggman while collecting Chaos Emeralds through the four main zones Splash Hill Zone, Lost Labyrinth Zone, Casino Street Zone, and Mad Gear Zone.

At the end of his journey throughout the zones, Sonic gave a final chase to Dr. Eggman. Just as Sonic had the doctor cornered, however, Eggman ascended to the sky and retreated to the E.G.G. Station Zone, a hover base built by Eggman. Sonic, however, jumped onto a rising rocket provided by Tails and chased after the doctor in hot pursuit. Onboard the E.G.G. Station, Sonic faced all of the past battle machines constructed by Eggman in past zones. After the fourth machine was destroyed, Sonic ran after Eggman to a slight depression in the floor; the mad genius then rose up to reveal his new creation, a rebuilt Death Egg Robot. Despite the mech's improvements, however, Sonic managed to defeat it, and he escaped the now exploding base, and landed in Splash Hill where his adventure ended for the time being.

Episode II
In Sonic the Hedgehog 4: Episode II, Sonic teams up with Tails, as Dr. Eggman joins a formidable alliance with Metal Sonic.

After having defeated Dr. Eggman onboard the E.G.G Station, Sonic spent the next few months relaxing from his adventures. This relaxing period was cut short however when Sonic heard that Dr. Eggman had returned and was up to no good on the neighboring continent. Sonic then sought out Tails and two of them headed out together in the Tornado to investigate the continent and Dr. Eggman's newest scheme.

With everything said and done, Sonic and Tails soon arrived in Sylvania Castle Zone, and after a rough landing, the heroic duo began investigating the surrounding area. Along the way, Sonic and Tails saw in the sky that the Little Planet had made its annual return to Earth, but now was covered in machinery. After some time of searching, the heroic duo found Dr. Eggman, and learned that the mad doctor had planned to turn the Little Planet into a power source for his newest Death Egg: the Death Egg Mark II. After defeating Dr. Eggman's Egg Serpentleaf, Sonic and Tails began a mad chase after the doctor to stop him.

As the two of them continued to chase Dr. Eggman, the duo passed through White Park Zone, where Sonic found himself and Tails attacked by Metal Sonic, whose return from Little Planet was set up by Dr. Eggman during Sonic the Hedgehog 4: Episode I. Despite finding his old rival more powerful than ever and determined to settle the score, Sonic and Tails managed to defeat Metal Sonic, and they continued chasing Dr. Eggman.

Sonic's and Tails' chase after Dr. Eggman eventually took them to the skies, where they followed the doctor in the Tornado. As they were about catch him however, Sonic and Tails were attacked by Dr. Eggman's Sky Fortress and pursuited by Metal Sonic in his Metal Carrier. After narrowly avoiding a barrage of missiles, Sonic and Tails made their way through the Sky Fortress with the Tornado, but were then attacked by Metal Sonic and his Metal Carrier. Sonic and Tails eventually managed to destroy the Metal Carrier however, after a tough aerial battle.

As the Sky Fortress was about to blow up, Sonic and Tails chased after Dr. Eggman though its interior, but the duo were then held back by Metal Sonic long enough for the doctor to escape in an rocket-powered escape pod. Seeing they did not have much time before the Sky Fortress exploded, Sonic and Tails searched for a way to escape. They soon found another escape pod, and used it to not only escape the Sky Fortress, but also chase after Dr. Eggman and Metal Sonic to the Death Egg MK.II.

Once onboard the Death Egg MK.II, Sonic and Tails began looking for Dr. Eggman and Metal Sonic. As they found them, the two pairs had a brief battle, which came to an end when Eggman and Metal Sonic escaped. As Sonic and Tails began chasing after them, Sonic found himself confronted by the lone Metal Sonic, who wanted a rematch with him after their last race on Stardust Speedway. Never the one to back down from a challenge, Sonic, alongside Tails, faced Metal Sonic in a clean race through the Death Egg MK.II. With Tails by his side, Sonic once again triumphed over his metallic doppelganger, and watched as he smashed into a wall near the finish line once more.

With Metal Sonic out of the way, Sonic and Tails went to face Dr. Eggman himself. They soon found the doctor, who confronted them in the Egg Heart, but Sonic's and Tails' teamwork managed to prevail over the contraption and destroyed it. As the duo saw that the Death Egg MK.II was now beginning to crash, they managed to escape it through two escape pods. As Sonic and Tails returned home, they watched on as the Death Egg MK.II shut down and was pulled away from the Earth by the Little Planet's orbit, thus marking the end of their adventure.

Sonic Colors
Sonic returned as the only playable character in Sonic Colors. In this game, Dr. Eggman claimed to have developed a sense of remorse for his past misdeeds and had constructed Dr. Eggman's Incredible Interstellar Amusement Park, an amusement park made of several planets, to make up for his past actions. Sonic, however, did not believe that Eggman had turned over a new leaf, but that it was just another evil plot. So, on the day before the opening, Sonic went to the amusement park with Tails to stop Eggman's plan.

Once there and taking in the beautiful views, Sonic remained sure that Eggman was up to something, despite Tails's doubts. While he was checking out the park, Sonic found Orbot and Cubot trying to capture two aliens with nets. Sonic moved in and saved the aliens, when the cyan alien suddenly went inside Sonic and turned him into a laser that zipped away. He later reached Tails, who was with the white alien he saved and was trying to build a translator so they could understand them. Sonic told Tails what happened, but Tails found it hard to believe. After failing to understand what the white alien was saying about Sonic's statement, Sonic decided to find Eggman and figure out what he planned to do with these aliens.

While Tails was busy building the translator, Sonic went out to explore the Tropical Resort and found Eggman, who was gathering aliens. Sonic revealed himself to Eggman and taunted him, but the doctor unleashed Rotatatron to kill him. Sonic easily destroyed it and (unintentionally) sent a piece of it into one of the towers in the process. He returned to Tails, who had the translator ready (albeit with a few bugs left to work out), and Sonic began questioning the alien. They learned that the alien's name was Yacker and that he came from an alien race called Wisps, whom Eggman had captured. Yacker then asked Sonic to save them and Sonic accepted the request.

As Sonic investigated one of the chained planets, he found a mysterious generator. After destroying the robot guarding it it and shutting the generator down, Sonic met up with Tails and Yacker. From them, Sonic learned about the Wisps' Hyper-go-on and Eggman is using it for an evil purpose.

As Sonic and Tails looked for Eggman on the next planet, the duo was taken by surprise when Eggman suddenly appeared and tried to brainwash Sonic with his Mind Control Ray that ran on Hyper-go-on energy. Sonic was fortuntely saved by Tails, but at the cost of Tails being affected by the ray instead. As he attempted to move in on the doctor, Sonic was blocked by the brainwashed Tails, but he absolutely refused to fight Tails when Eggman ordered the fox to attack him. Luckily, Eggman ran out of Hyper-go-on and Tails was freed. Eggman threatened Sonic that he would soon brainwash the entire universe and sent the local giant robot to defeat them before leaving.

After the battle and shutting down another generator, Sonic now knew Eggman's plan, but did not how to stop it. He learned from Tails and Yacker that Eggman captured the Wisps' planets with tractor beams that held them above Sonic's world, so if Sonic could destroy their generators, the planets would be free and Eggman would be cut off from his Hyper-go-on energy source. Having already broken two of without knowing, Sonic headed out to destroy the remaining three.

When arriving at Planet Wisp, Sonic was disgusted to see how Eggman transformed the planet and his treatment of the Wisps, and promised the Wisps to free them. He soon found the planet's generator and the robot protecting it. After defeating the robot, Sonic cockily began talking to its remains but was caught doing it by Tails, much to his own embarrassment.

Sonic and Tails continued to Aquarium Park where Sonic fought Admiral Jelly and destroyed it, thus freeing another planet. The two then went to the Asteroid Coaster where they worked their way into the main factory where all of the Wisps were turned into Nega-Wisps. Upon this sight, Sonic gained a new sense of seriousness and asked Tails to excuse him while he looked for the next generator. After finding the generator, Sonic fought the Frigate Skullian and broke the generator, thus not only freeing the planet, but also halting Eggman's harvesting of Hyper-go-on.

With all five generators destroyed, the planets and the Wisps were freed, and Sonic and Tails returned to the Tropical Resort where they started celebrating with the freed Wisps, thinking it was all over.

Unfortunately for Sonic, Eggman was ready to launch his mind-control weapon on the world, but the broken robot piece from Rotatatron that was unintentionally struck there by Sonic, caused the whole cannon to explode. As the park began to collapse, Sonic and Tails headed to Eggman's space elevator to get back home. When they arrived, Eggman showed up in the Egg Nega Wisp, determined to kill Sonic. Wanting his friend to be safe, Sonic pushed Tails into the elevator and launched him back home, while he confronted Eggman alone. After an intense fight, Sonic managed to defeat Eggman with the help of the Wisps and their Final Color Blaster. Unfortunately, the destruction of the cannon created a black hole, one that even Sonic was unable to outrun. As he was caught in the explosion, Sonic fell unconscious, but woke up to find the Wisps gathered around him, carrying him back to his planet, and as well stopping the black hole. As Sonic got up, he noticed that he was back home and was met by Tails. Yacker then appeared and thanked them, but told them that he had to go. Sonic and Tails then exchanged some high-fives with Yacker, and watched on as he joined the other Wisps and sent the planets back to their original place in the universe.

Sonic Generations
In Sonic Generations, the Sonic of the present, named Modern Sonic, teamed up with his younger self from the past, named Classic Sonic, as a new foe called the Time Eater appeared and began interfering with Sonic's history.

In the past of Green Hill, Classic Sonic was exploring until he heard a noise. He noticed the Time Eater in the sky as everything turned white. In the present day, a while after Sonic's adventures in Dr. Eggman's Incredible Interstellar Amusement Park, Modern Sonic arrived at a picnic and found his friends holding a surprise party to celebrate his birthday, which Sonic delightly joined. As Sonic enjoyed a birthday chili dog however, the Time Eater appeared and began to suck all of Sonic's friends back into different periods in Sonic's history. Modern Sonic tried to attack it, but was easily knocked back and passed out.

As he woke up later, Modern Sonic found himself in the White Space, and discovered Tails and Green Hill in a colorless, frozen state, but after passing through, he restored Tails and the area. Determined to find their remaining friends despite their peculiar situation, Sonic set off to check out the colorless Chemical Plant. Soon after, Classic Sonic passed through, confusing Tails, who mistook him for Modern Sonic.

As Modern Sonic (with the unknown help of Classic Sonic) restored Chemical Plant, Sonic met up with Tails again and told him how the place gave him déjà-vu. Both Sonics then continued through the White Space and restored more areas and their friends, each unaware of the other's presence.

The two Sonics later proceeded through a Boss Gate at the same time and found a glass with their counterpart at the other side of it. Both Sonics, however, mistook it for a mirror, along with his younger/older form as his reflection. The two then heard Dr. Eggman's voice through a door, and Modern Sonic shouted his name, bringing Classic Sonic to realize that it was not his reflection. While Modern Sonic was unimpressed by Dr. Eggman's threats, Classic Sonic ran towards Eggman's voice. Modern Sonic then tried to follow Classic Sonic, but was locked out.

After Classic Sonic met and destroyed the Death Egg Robot, he saw the Time Eater kidnap that time's Dr. Eggman. Modern Sonic later saw Classic Sonic exit the battle and wondered why there was two of him. Tails, who had also met his younger self, told the Sonics that they were traveling through time and space, which they believed the Time Eater was responsible for, and the Sonics decided to team up to stop it.

The two Sonics continued through the White Space, restoring the areas and their friends, one by one. After a while, the two learned from the Tails' that the Time Eater's actions ripped space and time apart, and damaged the world by sending damaged areas from different eras to the White Space, and that their speed was the key to restoring the space and fix the timeline.

After Modern Sonic defeated Perfect Chaos, they witnessed the Time Eater being repelled by a color-drained Chaos Emerald and decided to collect all seven emeralds, assuming them to be its weakness. Later, as the Chaos Emerald regained its color, Modern Sonic and Classic Sonic raced for it, with Modern Soinc using the Boost to catch the Chaos Emerald, much to the amazement of his younger self. Afterwards, after Modern Sonic later beat Eggman in the Egg Dragoon, the Time Eater came by and kidnapped Eggman again, much to the group's confusion.

The Sonics eventually obtained all seven Chaos Emeralds and confronted the Time Eater in its own domain. As Modern Sonic told it to give up, Dr. Eggman and his past-self, Classic Eggman, revealed themselves as the ones controlling the Time Eater in an attempt to erase Sonic from the timeline so that the doctors would be victorious in the present. Unconcerned, since they always beat the doctors, the two Sonics began fighting, but got knocked out by the Time Eater. While passed out, the Sonics got support from all of their friends, allowing the Chaos Emeralds to activate. The two Sonics then awoke and transformed into their Super States. Together, they defeated the Time Eater and stopped the doctors' plan, and returned back with their friends to where Modern Sonic's birthday party left off.

During the party, Modern Sonic thanked Classic Sonic for his help and hoped that he had learned some tricks. Classic Sonic replied by attempting to perform the Sonic Boost, but did not manage to keep it going, though Modern Sonic encouraged his younger self nevertheless for the effort. As Classic Sonic and Classic Tails were heading back to their own time, Modern Sonic told Classic Sonic as they left that he had a great future ahead of him. (NOTE: Again, a trait of Sonic's is compromised for the running gag dynamic with Amy. However, this is the first time he bluntly took action towards her advances by placing his hand over his face rather than him usually running away. Also note that the personality of Classic Sonic is heavily mellowed compared to the marketed "hedgehog with an attitude" persona in the 90s. There is also contradiction for him being mute while other Classic forms of the characters have voices.)

Sonic Lost World
In Sonic Lost World, Sonic and Tails were chasing after Dr. Eggman, Orbot and Cubot to free some animal friends they had captured. As they chased the doctor and his lackeys through the sky in the Tornado, Sonic told Eggman to release the animals in his capsule, and the doctor dropped it from the sky, forcing Sonic and Tails to go after it. After Sonic missed a chance to open the capsule, and Tails turned the Tornado around to go after it, the plane was damaged by Eggman's laser, causing Sonic and Tails to fall from the sky. As they descended, Sonic and Tails encountered the Lost Hex, which they were forced to land on.

Arriving in Windy Hill, Sonic found the dropped capsule when he was contacted by Amy and Knuckles. When Sonic told them the status on his rescue mission, Amy pleaded Sonic to save the rest of the animals, which Sonic promised. Not long after, Sonic was attacked by Zazz, but he managed to defeat him. Soon after, Sonic found Dr. Eggman, who introduced the Deadly Six, a group of Zeti - Zazz included - that he controlled, to him. As Eggman then left Zazz to finish him while the doctor escaped with the rest of the Deadly Six, Sonic fought and defeated Zazz again. After the battle, Sonic met up with Tails and they took off in the repaired Tornado.

While moving through Desert Ruins, Sonic encountered Zomom twice, but defeated him in both encounters. Soon after, Sonic and Tails snuck up on Eggman when the he was scolding the Deadly Six for their failures. Noticing that Eggman used a conch to keep the Deadly Six in line, Sonic knocked the conch out of Eggman's hands, despite Tails' warning. This proved to be a mistake, however, and the Deadly Six rebelled against Eggman by talking control of his Badniks and using them to attack everyone present. When Tails got injured in battle, Sonic abandoned the fight to take Tails to safety, escaping with Eggman, Orbot and a decapitated Cubot.

Escaping to Tropical Coast, Sonic was berated by Eggman for making him lose control of the Deadly Six, until he got the doctor to leave while he and Tails got things under control. After Sonic defeated Master Zik, he and Tails was contacted by Amy, who informing them that something was sucking the life out of the world, and Sonic promised to try and stop it. Following another battle with Master Zik, Sonic and Tails met Eggman again, who revealed that the Deadly Six had gotten hold of his Extractor, which they were using to drain Earth of its energy to make themselves stronger, until the planet was destroyed, which Sonic saw matched Amy's report. Eggman then suggested that they teamed up, with Sonic getting Eggman to the Extractor so the doctor could shut it down properly. Despite his dislike about working with Eggman, Sonic agreed to it.

Arriving at Eggman's factory, Sonic tried to break up an argument between Tails and Eggman when he discovered that Tails was mad at him for trusting Eggman more than him to shut down the Extractor. Sonic tried to say that they needed Eggman's help because the world was in danger because of Sonic's actions, but to no avail. After meeting and fighting Zeena, Sonic and the others were contacted by Zavok, who stated the futility of their actions, until Eggman interrupted them. After another fight with Zeena, Sonic rebuffed Eggman's plan to destroy the Deadly Six by destroying the Lost Hex, seeing that it would kill countless innocent as well, when Tails got attacked by Cubot when he put his head on a Crabmeat. Before Sonic could act, however, Eggman saved Tails, leaving Sonic confused by Eggman's conflicting behavior, while he scolded Tails for endangering himself.

After getting to Silent Forest, Sonic found and tried to open a capsule, but Tails pushed him away, having discovered it was a trap set by the Deadly Six to capture Sonic. Sonic then witnessed Tails getting caught and teleported away, leaving Sonic ridden with guilt for letting Tails get caught and frustrated at his inability to save him. Soon after, Sonic met Zor and demanded Tails back, before fighting him, though Zor managed to escape.

Getting to Sky Road, Orbot asked Sonic if he could become his sidekick now, but Sonic insisted that he would not fail again and that he would save Tails. Soon after, Sonic found Zavok and was horrified to hear that Zavok planned to turn Tails into a robot, before taking on Zavok and defeating him. Distraught, yet determined to save Tails, Sonic continued forward, until he contacted Amy, who told him that it was too late for her and Knuckles, before losing contact with her. Zavok then appeared and taunted Sonic with the loss of his friends, and Sonic battled and defeated Zavok.

When Sonic and Eggman arrived at Lava Mountain, the location of the Extractor, they were attacked by Zazz and Zomom, who had been powered up by the energy of the planet. The two Zeti destroyed the bridge Sonic and Eggman stood on and they nearly fell into a lava pit. Sonic, however, was saved by Eggman, who sacrificed himself to save Sonic by throwing him back on solid ground while the doctor himself fell into the lava pit. After escaping his death, Sonic faced and defeated Zomom, Master Zik and Zazz for good. Some time later, Sonic tried unsuccessfully to contact Amy and Knuckles, and was dishearted when he realized that he was all alone now to finish this battle. Sonic met eventually met Zavok, Zeena and Zor, and was shocked and angered to see that Tails had seemingly been turned into a robot. When Tails was ordered to kill Sonic when he refused to serve them, however, Sonic discovered that Tails had tricked the Deadly Six into thinking that he was turned into a robot. Relieved to have Tails back, Sonic fought with renewed will and defeated Zeena, Zor and finally Zavok for good.

Having finished the Deadly Six, Sonic and Tails got to the Extractor to shut it down, only to discover that the machine was already off. Eggman then showed up in a new mech, revealing that he faked his death so that he could charge his mech with the world's energy, while Sonic fought the Deadly Six, and that he now planned to move out to conquer what was left of the world, but Sonic fought Eggman's mech and defeated it. As Tails made the Extractor return the world's energy, Sonic apologized to Tails for ever doubting him, mending their friendship. When Eggman then tried to escape using his jet pack, Sonic revealed that he had removed its exhaust pipe, causing Eggman to fall down from the Lost Hex. Sonic and Tails then returned to Earth and met up with Knuckles and Amy there. Glad for the adventure to be over, Sonic lay down in the grass to take a nap to rest from the ordeal. (NOTE: Sonic's flawed side is noticeable throughout the game, but certain scenes show it conflicts with his other established traits to fulfill the plot rather than being a natural display of his mistake. One example is Tails' accusation towards Sonic of trusting Eggman over him about shutting down the machine. Despite Sonic saying he does trust his closest ally, he deflects the issue towards himself of the guilt towards his mistake rather to ease Tails' concern. This contradicts his traits of being understanding and insightful of those in pain or doubt such as Merlina in the Black Knight. Another instance is his meeting with Zor in Silent Forest after feeling guilty of Tails' capture. He immediately confronts Zor with his words, but not with his actions as Zor begins to walk away while Sonic's usual impulsive nature is halted for the sake of the scene. This conflicts with his statement of regretting not being fast enough to rescue his friend when presented the opportunity to quickly force the information he needed from Zor.)

Sega Superstars Tennis
In SEGA Superstars Tennis, Sonic is a playable character. He played tennis with other SEGA characters.

Sonic & Sega All-Stars Racing
In Sonic & SEGA All-Stars Racing, Sonic is one of the playable characters in the game. For the racing in this game, he uses hie vehicle the Speed Star.

Sonic & All-Stars Racing Transformed
Sonic drives his Speed Star again, now tricked out to turn into a plane and a boat.

Mario & Sonic at the Olympic Games
In Mario & Sonic at the Olympic Games, Sonic is a playable character, where he met Mario at the Olympics. Sonic's team of Tails, Knuckles, Amy, Blaze, Shadow, Vector, and Doctor Eggman competed against Mario's Nintendo team of Luigi, Yoshi, Peach, Daisy, Wario, Waluigi, and Bowser.

Mario & Sonic at the Olympic Winter Games
In Mario & Sonic at the Olympic Winter Games, Sonic is a playable character where he competed with Mario at the Winter Olympics in Vancouver, joined by new teammates Silver and Metal Sonic.

Mario & Sonic at the London 2012 Olympic Games
In Mario & Sonic at the London 2012 Olympic Games, Sonic is a playable character in his third Olympic appearance with Mario in London.

Mario & Sonic at the Sochi 2014 Olympic Winter Games
Sonic will make his fourth Olympic participation in Mario & Sonic at the Sochi 2014 Olympic Winter Games.

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, Sonic is of the playable characters in the game. He can be unlocked in the game by doing any one of these four tasks:


 * Play 300 Brawls, then defeat Sonic.


 * Complete Classic Mode with 10 characters, then defeat Sonic.


 * Fight for 10 hours or more (cumulative between multiple players) in Brawls, then defeat Sonic.

In the Adventure Mode: The Subspace Emissary, when the Nintendo heroes got through a maze and confronted the final boss Tabuu, Tabuu prepared to turn everyone into trophies, but a blue blur came out of nowhere and broke Tabuu's wings. The blur landed on a mountain, revealing himself as Sonic. Sonic taunted Tabuu and helped the Nintendo heroes defeat him, restoring the world back to normal.
 * Have Sonic join the player's party in the Subspace Emissary.

Sonic also appears in the game as one of trophies and two Stickers.

Super Smash Bros. for Wii U/3DS
Sonic was confirmed for Super Smash Bros. for Nintendo 3DS/Wii U on 1 October 2013, making it his second appearance in Nintendo's Super Smash Bros. series. He is the first third-party veteran in the series.

Cameos
Video games such as Dr. Robotnik's Mean Bean Machine, Tails Adventure, Knuckles Chaotix and Shadow the Hedgehog starred supporting characters of the Sonic series; in some of them Sonic had a cameo role. The hedgehog has also made cameo appearances in numerous other Sega games such as Daytona USA.

Appearances in Other Media
Sonic has appeared in several different media (such as TV series and comics) outside of his mainstream games series. These series often take place in their own unique continuities, which differ greatly from the games in terms of plot, setting, and even Sonic's characterization. Some versions of Sonic from these alternate continuities are listed here.

Adventures of Sonic the Hedgehog
Adventures of Sonic the Hedgehog was the first cartoon to featured Sonic and had a very comical take on Sonic's adventures. In this media, Sonic is a world roaming Freedom Fighter with a lifestyle similar to a tramp, who fiercely defends the citizens of Mobius from the evil schemes of Dr. Ivo Robotnik and his lackeys Scratch and Grounder, who are easily being deceived by Sonic's numerous creative disguises no matter how pathetic or bizarre.

One day, he came across a young orphan named Miles "Tails" Prower who he decided to adopt as his younger brother, as the young fox had none to live with and they became as close as a real family. While Sonic has his trademark atttude in this media, he also tries his best to stand out as a responsible role model for the innocent Tails, especially during the Sonic Sez segments.

Sonic the Hedgehog (TV series)
Sonic the Hedgehog, originally broadcast on Saturdays on ABC, was broadcast concurrently with the syndicated Adventures series in the United States. The Archie Comics continuity was based heavily on this series and features a similar background for Sonic. In this media, Sonic lived in Mobotropolis with Princess Sally and the future Freedom Fighters during their childhood until Dr. Robotnik invaded the kingdom, enslaved the people with the Roboticization technology and took control of the planet.

Sonic and his friends however managed to escape the tyrant by fleeing into the Great Forest where they built a village named Knothole to hide from Robotnik. There Sonic, Sally, and the others then formed the Freedom Fighters and began a ten year long battle with Dr. Robotnik to take back their planet, with Sonic being one of the main leaders and their primary agent.

Sonic Underground
Sonic Underground, a show in the US, United Kingdom and France, ignored the continuity of the previous series and games and instead introduced two siblings and Sonic's mother, named Sonia, Manic, and Queen Aleena respectively. In this media, Sonic was born as the heir to the throne of Mobius, along with his siblings, Manic and Sonia. Shortly after their birth however, their mother Queen Aleena was dethroned by Dr. Ivo Robotnik and they became wanted, but the Oracle of Delphius prophecized that Aleena and her children would one day defeat Robotnik, but only if she left her children in the care of others until then.

Sonic himself was left in the care of a regular family, but during his early childhood his adopted family was captured and roboticized. He then joined his Uncle Chuck and the Freedom Fighters in the battle against Robotnik over many years. One day however, Sonic was approached by the Oracle who revealed his origin and family. Sonic soon after reunited with his siblings and together they formed the band Sonic Underground where they fought Robotnik while searching for their mother.

In this media, Sonic possess a medallion that transforms into an electric guitar/laser rifle.

Sonic the Hedgehog: The Movie
Additionally, there was an OVA movie that featured Sonic, Tails, Knuckles, Dr. Robotnik and Hyper Metal Sonic. In this movie. Sonic and Tails lived on Planet Freedom, but were one day called by Doctor Robotnik to battle an evil robot named Metal Robotnik and save their planet from destruction. This was however a trick on Robotnik's behalf so the evil doctor could copy Sonic's data into his Hyper Metal Sonic robot. After the doctor succeded in his plan, Sonic and his friends tried to stop this metallic copy from destroying the world.

Sonic X
In the anime series Sonic X, Sonic originally lived on a parallel version of Earth in another dimension. During one of his battles with Dr. Eggman however, a massive Chaos Control blast occurred and Sonic, his friends and Dr. Eggman were transported to the human world. Shortly after arriving, Sonic nearly drowned in a pool, but was saved by Chris Thorndyke, who Sonic became friends with. Over time, Chris came to have a strong bond with Sonic as he lived a lonely life since his famous parents were always busy.

Sonic eventually settled down on this new world with his friends and became a famous hero among the human population as he and his friends protected the world from Dr. Eggman as the doctor attempted to rebuild his Eggman Empire in this new world. Like the other television series, the show had an original storyline not present in any of the games, although it can be viewed as an elaboration upon the Sonic Adventure games' storylines. Eventually, Sonic and everyone from his world were forced to return home as their presence threatened to freeze time. Before Sonic could return home however, he was kidnapped by Chris who did not want him to leave, but Sonic eventually made Chris come to terms with his feelings and Sonic returned home.

In season 3, Sonic teamed up with his friends and Chris, who had just arrived in Sonic's dimension, to fight the Metarex, an alien race of cyborgs that was a threat to the safety of the entire galaxy. With everyone's aid, Sonic managed to defeat the Metarex and their leader Dark Oak and saved the universe. Upon returning to his home planet, Sonic had his goodbye with Chris who returned to his world and Sonic himself went back to his normal battles with Dr. Eggman once more.

Sonic Boom
Sonic will appear as the main character in the new upcoming CGI animated TV series, currently under the working title of Sonic Boom, which will air in Fall 2014.

Books and comics
Sonic's first comic appearance was in a promotional comic printed in Disney Adventures magazine, which established an origin for Sonic involving the transformation of kindly scientist Doctor Ovi Kintobor into the evil Dr. Ivo Robotnik. Numerous British publications, including "Sega handbook" Stay Sonic (1993), four novels published by Virgin Books (1993–1994) and the comic book Sonic the Comic (1993–2002) used this premise as their basis.

The American comics published by Archie Comics, Sonic the Hedgehog (1993—present), Sonic X (comics) (2005—2009) and Sonic Universe (2009-present) are based on the settings established by earlier animated TV series, the ABC Sonic the Hedgehog (SatAM) cartoon and the Sonic X anime respectively.

In Japan, various Sonic manga have been published.

Shogakukan manga
In the manga series by Shogakukan, Sonic is the heroic alter ego of a young, timid hedgehog boy named Nicky. Nicky transforms into Sonic whenever he wishes he had the strength to overcome a dangerous or stressful situation, but nobody (even Nicky) is aware of this transformation.

Nicky's girlfriend Amy (a prototype of Amy Rose) also has a crush on Sonic, and Nicky's father Paulie, a pilot, claims that Sonic once saved his life long before Nicky was even born.

Archie Comics
In the Archie Comics, Sonic is a Freedom Fighter and is the most famous hero on Mobius. He is best known for his defeat of Dr. Ivo Robotnik and his heroic actions preventing the Xorda from destroying Mobius and its solar system. Raised in Mobotropolis before Ivo Robotnik's coup, Sonic was an average child except for his abnormal speed. Sonic lost his parents to the roboticizer and was taken in by his Uncle Chuck until he too was roboticized. During Robotnik's Coup d'état, Sonic and a few others were herded to Knothole Village by the Original Freedom Fighters. It was from them that Sonic got the inspiration that would one day make him a hero.

As Sonic developed his incredible speed, his attitude became legendary. Irreverent, confident, impatient, and energetic, Sonic fought constantly to overthrow Robotnik Prime and continues the fight against his successor, Robo-Robotnik (later renamed Dr. Eggman).

After the Xorda attack, Sonic was teleported into space, where he spent a couple months trying to return to Mobius. But when he returned, a whole year had passed, and things were very different. Since returning to Mobius, Sonic has fought off the newest incarnation of Enerjak, overcome the destruction of Knothole, dethroned his evil counterpart Scourge the Hedgehog from his tyrannic rule over Moebius, briefly ended the Second Robotnik War, defeated the Iron Dominion and stopped Operation: Clean Sweep from destroying reality, all while facing complex problems between him and his friends, and political troubles in the Kingdom of Acorn/Republic of Acorn on the homefront. Following the disbandment of the Knothole Freedom Fighters and a series of losses on his behalf, Sonic has since assumed leadership of Team Fighters to continue the fight against Dr. Eggman. When the second Genesis Wave later was unleashed, Sonic teamed up with Mega Man to bring their two universes back to normal.

In addition to his uncanny speed, Sonic has the ability to absorb Chaos Energy. Absorbing a great amount of this energy causes him to transform into Super Sonic. As Super Sonic, all of his natural abilities are enhanced and he gains the ability to fly, among other strange powers. His skin and eye colors change to yellow and red respectively, and he takes on an aura of yellow energy. It has happened also that Sonic has transformed even further into Ultra Sonic. Ultra Sonic is even more powerful and has the ability to adapt to his surroundings by taking on new forms.

Sonic the Comic
In Sonic the Comic, Sonic was once an ordinary brown (though still fast) hedgehog on the planet Mobius. He encountered a kindly scientist named Doctor Ovi Kintobor, who performed experiments on his speed. An explosion resulted in his spines fusing together and turning blue. A later experiment, involving Kintobor's attempts to rid Mobius of evil, transformed the good doctor into Ivo Robotnik. After several unsuccessful attempts to take over the world (as depicted in the first two Sonic games), Robotnik finally managed to conquer the planet by sending Sonic six months into the future. On his return, Sonic took it upon himself to form a group of Freedom Fighters to depose Robotnik, which they finally managed to do in the series' landmark 100th issue.

As in other continuities, Sonic is aided in his adventures by his loyal sidekick Tails, as well as Amy Rose and original characters Porker Lewis, Johnny Lightfoot, Tekno the Canary and others. He has a friendly, though still quite intense, rivalry with Knuckles the Echidna, who frequently accuses Sonic of bringing trouble onto his Floating Island.

Sonic can turn into Super Sonic in this continuity without exposure to the Chaos Emeralds (because of a dose of radiation he received when the Emeralds were first brought together), but in this form he is out-of-control, bordering on psychotic, and he attacks friends and enemies alike. The two were separated for an extended run, but re-united in the series' final story arc.

Personality
Sonic has been described as being "like the wind"; a drifter that is always on the move and is noted for being free-spirited and adventurous. He values freedom above all else, living his life according to his own rules, rather than the standards of those around him, and enjoys nothing more than traveling across the endless boundaries of the world while searching for new adventure. With a strong passion for enjoying life, Sonic is never dwelling in one place for too long and is always moving forward to look for new experiences, making his life a series of adventures and events, while enjoying his freedom. Sonic is mostly laid-back, cool and enjoys relaxation, though he is often impatient with slower things and firmly stands for freedom. He also bears a fondness for the beauty of nature and has been shown to be a protector of it ever since the first Sonic game in 1991. This is the reason he first came into conflict with the evil Dr. Ivo “Eggman” Robotnik and his destructive way. Nature has thus remained a common point of contention in their feuds to this day. According to the Sonic Unleashed manual, Sonic “cannot look away when someone is in trouble”. He is never the one to rest in the face of injustice or oppression. He hates evil in all its forms and can easily be riled up about it; if he witnesses someone being oppressed, are suffering from injustice or are simply depressed or despairs due to others' actions he will not show a moment of hesitation and will instantly step in to help those in need, even if it means that his actions will be met with contempt, as stated in Sonic and the Black Knight. Sonic is also known for indomitable will, always wanting to keep up the good fight, even far past his own physical limitations. Sonic will try to hide pain, fear, (unless a friend is in trouble or Amy gets angry), and exhaustion. Sonic usually sees his heroics and fighting evil as an opportunity to have fun, making him somewhat of a thrill-seeker. However, in times of crisis, he focuses intensely on the task at hand and sees it as truly serious with no real fun involved, as if his personality had undergone an astonishing change. Even so, Sonic has a very forgiving side, and is willing to bury the hatchet if his enemies are willing to repent of their evil ways. Regardless of the countless foes he has fought throughout the series, he bears no noticeable ill will to any of them. Most notable towards Dr. Eggman, whom has constantly tried to destroy him to complete his schemes, however Sonic is satisfied with merely stopping him, also in occasions where Eggman helps Sonic and co. to save the world (although for his own interests, mainly because he could not take over the world, if it's destroyed) he never rejects his help.

Sonic is shown to be extremely loyal to his friends. Though he sometimes teases or messes with them, finds them annoying, or seems absent when they are talking to him, Sonic genuinely cares for each of his friends and is always willing to help or support them if needed, even without a reason. If any of his friends seem to be in danger, Sonic will put them above all else and see to their safety before doing anything else. Equally, Sonic is always willing to accept help from his friends, if offered, and will show great trust in them. Sonic is not above leaving his friends hanging or even endanger them by accident, such as when he and Tails left Amy behind in Sonic Adventure 2 when they were aboard the Ark which led to her being captured by Eggman. Despite taking risks with his friends, however, Sonic always take them into account and never has any intention of making any of them unhappy.

Sonic often acts very proud and is a showoff. While While he has been known to show some form of modesty when taking compliments like in Sonic and the Secret Rings where he refutes to being called, "Legendary Hedgehog", Sonic does have his moments of overconfidence like in Sonic and the Black Knight when he balked at Merlina for preventing him from attacking the titular villain head on. In addition to these flaws, Sonic's impulsive nature has, at times, caused him and others trouble. This is shown in the opening cutscene of Sonic Unleashed when Sonic storms Eggman's base without thinking of traps, which he ultimately falls into one. Despite his thrill-seeking, hyperactive, and smug demeanor, Sonic has shown many times to be much more insightful than he usually lets on. In the earliest display of this insight would be in Sonic Adventure, where Sonic was able to understand how simply resealing Chaos in the Master Emerald while Chaos was still suffering from all of its rage would solve nothing in the end. Other instances include in Sonic the Hedgehog (2006), in which Sonic was able to give Elise valuable and comforting advice and in the end of Sonic and the Black Knight, where he was able to give Merlina similar words of encouragement and comfort. This insight, combined with a charismatic personality, allows Sonic to get along with virtually anyone he meets even if at one point they were his enemies.

The Japanese version of Sonic Advance 3 strategy guide, Sonic Unleashed and Sonic and the Black Knight states that Sonic's favorite food is chili dogs. He enjoys music, but seems to have an special interest in rock music. Some official character art and a television commercial for Sonic Adventure suggests that he has a personal hobby as a Disc Jockey. Furthermore, it is displayed in Sonic Rush that Sonic also enjoys break dancing as it is one of his primary ways for filling up his Rush meter. His battle moves in Sonic Battle are also based on break dancing, as mentioned in the attack descriptions. He also breakdances in Sonic Advance 3 if he finishes a level in a short-enough time. One of his taunts in Super Smash Bros. Brawl is him break dancing and saying, "C'mon, step it up!" (or just "Come on!" in the Japanese version). He will also breakdance if he gets first place in the Mario & Sonic at the Olympic Winter Games. In Sonic Generations, Sonic will breakdance if an S rank is achieved.

Speed
Sonic is known best for his speed, with the ability to run at speeds greater than Mach 1, which is at the blistering speed of 768 mph (1,236 km/h). This is evident in many games, where Sonic is recorded to run at speeds faster than 765 mph (1,231 km/h). In Sonic Unleashed, the checkpoint posts (Star Posts) also act as radars that clock Sonic's speed when he passes them. Due to the fact that his speed increases the longer he's boosting, it's possible for the checkpoint posts to show Sonic's max speed in-game, being able to clock him going at over 2,500 mph (4,023 km/h). It is also stated in the Sonic Adventure DX manual that "He's the world's fastest, hypersonic hedgehog" which is at a staggering speed ranging from 3,840 mph (6,180 km/h) to 7,680 mph (12,360 km/h). He is occasionally referred to as "the fastest thing alive," and can run backwards at full speed just as well as forwards, as shown in the Team Sonic opening cut-scene of Sonic Heroes. Due to such speed, he is able to scale right up the walls of buildings, or similar structures, and can also run right over water.

It is unknown how much faster Sonic can run beyond Mach 1, although it is variously assumed that he can. In Sonic Battle, it is stated that he can move several times the speed of sound and in Emerl's story, Sonic takes on and defeats the Gizoid in under 30 seconds, before the Final Egg Blaster fires in that time. It is also believed that Sonic can move faster while in spinball form than running, possibly even reaching the speed of light due to the various proofs, such as in Sonic Adventure, Sonic Adventure 2 and Sonic Heroes, where he could use the Light Speed Attack which, stated by Tikal, attacks enemies at light speed. He can likewise achieve light speed movements with his Light Speed Dash.

His speed does not seem to have certain weaknesses in that recklessness (the possibility of crashing into unintended targets) and "straight-line only" concepts are invoked, which implies that Sonic relies on his animal instincts to control the line of his running paths, and he may as well have already adjusted to controlling himself at such a speed in constant moments. Sonic is also shown to be able to run in full tight circles, thus is not exposed to the weakness of only being able to run fast in straight lines. Should he be running at fast uncontrollable speeds, he can use the Sonic Drift to properly control his momentum, and even crash into foes with it.

Physical Abilities
In line with his super speed, Sonic has displayed amazing feats of movement and has the reaction time to match. He possesses great acrobatic skills and agility, alongside astonishing reflexes, making him able to avoid large and small obstacles with precise jumps and delicate movements, such as his Quick Step, despite the speed they are approaching at. When launched into the air, he can perform several tricks before finally landing on ground. He has also shown on several occasions that he can jump incredibly long distances, up to several hundred meters, possibly by applying speed to his jumps.

In terms of physical strength prowess, Sonic has often been noted for lacking overall physical strength in comparison to other characters in the series. However, it is possible that Sonic might actually possess a degree of superhuman strength (though nothing in comparison to Knuckles' strength). He has been shown to be able to carry things as large as himself, even while running full speed, (such as carrying Tails to safety in Sonic Lost World.) Sonic's Spin Dash and other spin forms are strong enough to cut through enemies (though not all shields), burrow through the ground, smash through surfaces by stomping, or break down walls. However, it is debatable whether the attack's main power comes from his supersonic speed or his superhuman strength, or a combination of both. Most moves that Sonic performs in fighting games involve his feet and legs more than his hands, which suggests that Sonic's legs are more powerful than his arms. This does not mean that Sonic's arms are not powerful as well, as he has been shown being able to tear parts from robots' bodies with brute force alone.

Several times, Sonic has been shown to have great resilience to physical damage. He can survive getting caught in the crossfire from all angles by Eggman's robots (which only knocked him out cold briefly), and he can smash through several robots in a row with his fist without showing any sign of pain or injury. It is also worth noting that, for nearly all the battles Sonic has endured, he has never been crippled, nor has he displayed any serious injuries. It is also shown in various games that Sonic can survive free-falls from extreme heights, bordering at the edge of space. In Sonic Adventure, he fell face-first from a high point in the atmosphere twice, merely shaking it off after landing, and additionally in Sonic the Hedgehog 2 and Sonic & Knuckles, Sonic is able to survive atmospheric reentry unharmed. Sonic also displayed the ability to heal himself by vibrating his body at supersonic speeds.

Sonic also possesses an indomitable force of will; in situations where most others would give up and resign themselves to defeat or imprisonment, and in situations where he is severely outnumbered and outgunned, he always forges on, never loses faith in himself and never quits or submits. This character trait is most noticeable in Sonic Unleashed, wherein, thanks to his will, he is one of the few people on the planet who is immune to the influence of Dark Gaia. This is also shown in Sonic Chronicles: The Dark Brotherhood, where the Voxai Overmind attempts to use mind control on Sonic, and he resists when all other characters fail to do so, though he possessed some protection against it by having a Chaos Emerald filled with the Overmind's power. It appears once more in Sonic and the Black Knight, where he continues to fight Merlina despite having Caliburn broken in half and beaten to the point where he could barely stand. The only time his will did not work was in Sonic Rivals 2, when he was possessed by the Ifrit in Tails' story scenario. It is safe to assume though, that if he does get possessed, he does all he can to regain control.

Sonic has also demonstrated the ability to harness the power of the Chaos Emerald for his own use. With a Chaos Emerald, Sonic can perform Chaos Powers, such as Chaos Control which lets him warp time and space, and occasionally gain a boost in power.

It is safe to say that Sonic is far stronger, faster, and more skillful than he lets on. Only in truly bleak situations does he reveal his true power - his fight with Ultimate Emerl, who had the abilities of every character, all seven Chaos Emeralds and the power of the Final Egg Blaster (therefore being mainly superior to him in almost every way possible), is a prime example of this, and Sonic was able to defeat him. It would appear that his cockiness, overconfidence and reluctance to fight at full power stop him from truly being considered the most powerful character in the series. Also, Sonic is often reluctant to use his Chaos Powers, and relies on his speed and other abilities in his arsenal in most cases.

Combat Skills
Despite not having received any known training in martial arts, the many years of battles Sonic has been through has made him a skilled fighter and a profound user of hand-to-hand combat, being able to go up against others who have spent most of their lives training for battles. It has also been noted by people, such as Blaze and Shadow, that Sonic's combat skills are always improving, most noticeably being his victory over the Egg Emperor and Perfect Chaos in the different versions of Sonic Generations, where both opponents previously required additional support and power for Sonic to defeat, but could this time defeat on his own using his own skills.

Fighting Style
In many of the fighting games where Sonic has been playable, it is shown Sonic mainly tend to use his legs and fast footwork to attack his opponents as his greatest strengths lies in his legs, though his is also shown to use his arms in battle as well. When fighting opponents hand-to-hand, Sonic makes use of his greater speed to deliver fast strikes to his opponents, which either allows him to deliver several strikes in a spilt second, or to increase the force behind his strikes in order to compensate for his lack of physical strength. For stronger physical strikes, he tends to perform Spin Attacks, Spin Dashes and Homing Attacks to knock his opponents back and to deal more damage.

Sonic's Back-Grab in Super Smash Bros. Brawl has him backflip backwards (while holding the opponent), land on the ground, and kick the opponent at a decent knockback. His forward smash consists of Sonic swinging his arm around for a short time and then releasing a charged punch (which might resemble his buzzsaw type attacks, and resembles his wind-up punch from Sonic the Fighters). This attack is one of his most powerful smash attacks in terms of knockback. Also as a nod to his footwork, Sonic also at times like in Sonic Battle, applies some forms of Capoeira to his combative footwork, especially in his Sonic Flare attack.

Even though he does not prefer to use weapons in combat (mainly dissing firearms as said in Shadow the Hedgehog), Sonic is shown to greatly excel in swordsmanship as seen in Sonic and the Black Knight. Even after having just picked up a sword, Sonic was able to slay a dragon using a sword alone and after receiving formal training from Caliburn, Sonic becomes capable of going up against and defeating the best knights in the world of Camelot in duels with swords, such as Lancelot, Percival and even King Arthur. By using his speed and moves in line with his swordplay, Sonic can make quick and swift slashes and becomes a buzzsaw when spinning around with his sword, making him a dangerous force to be reckoned with. He also has basic knowledge of how to use a Piko Piko Hammer to fight as seen in Sonic Advance 3.

Techniques and Moves
Many of Sonic's fighting moves are variations on the tendency for hedgehogs to roll into tight balls for protection. Since his introduction in the first Sonic the Hedgehog, Sonic's primary offensive maneuver is the basic Spin Attack. As Sonic jumps or runs, he curls up and spins into a spiky ball when in motion that can damage, destroy, mow down, or burrow through many obstacles or foes. Later games in the series expanded on this basic attack. Two of these enhancements are now basic moves: the Spin Dash was introduced in Sonic the Hedgehog 2 and involves Sonic spinning on the spot before blasting off at full speed, and the Homing Attack, officially introduced in Sonic Adventure, although unnamed variations of it appeared in Sonic 3 & Knuckles and Sonic 3D Blast, in which Sonic dashes in midair toward a target.

The Super Peel Out, or Figure 8 Dash, made its debut in Sonic the Hedgehog CD, but since has only had minor recurrences in the Archie Comic series and anime. In the Figure 8 Dash, Sonic stays pivoted in one place and his legs move fast enough to create the illusion of an infinity symbol (more correctly a Möbius strip) beneath him in red. He holds this and then blasts forward.

Another technique, the Blue Tornado or Sonic Wind is when Sonic jumps into the air, and creates a whirlwind by circling a particular spot at high speeds which can throw his opponents into the air or blow away armor and weapons.

One of Sonic's newest signature moves is the Sonic Boost, a technique where he can increase his speed further and turn himself into a projectile by moving at such high speeds that he destroys any enemy caught in his path. He does not even need to have contact with the ground in order to execute the move as seen in Sonic Generations, and can use it to practically fly immense distances through midair. Similar to his healing ability in Sonic Battle, Sonic seems to be able to displace almost anything with his supersonic attributes. Also in Sonic Generations, he can even make objects accelerate faster with no need to expend power, as on Planet Wisp he can land on moving coal carriers and make them carry at a higher speed.

In the Sonic Storybook series Sonic can perforn different techniques related to the Soul Gauge; the Time Break lets him slow down time, the Speed Break increases his speed and makes him invulnerable, and his Soul Surge lets him attack with lightning fast sword slashes.

Miscellaneous Skills
It is assumed that Sonic can control the strength or hardness of his quills. They appear to be extremely hard like buzzsaw blades when he is in spinball form, capable of shredding through several layers of reinforced steel to just about anything with enough speed. When he is not in ball form, they appear soft and flimsy like rubber. In Sonic Heroes, his quills (and body) are durable enough to slice through battleships without even moving at the speed of sound. In Super Smash Bros. Brawl, he can temporarily increase the durability of his quills to hit opponents in his Up Throw. In this move, he throws up an enemy, goes into a push-up type pose, and flares up and hardens his quills for the enemy to land on.

As shown in Sonic Battle, Sonic possesses the ability to heal himself, presumably by vibrating his molecules, and that he can launch shockwaves of air by spinning in his spinball form at high speeds.

In Sonic and the Secret Rings, during Dinosaur Jungle, Sonic mentions that his quills can sense danger, before being attacked by a dinosaur.

In the Sonic Riders series, Sonic has proven himself as a world-class Extreme Gear rider and is able to go head-to-head with the best Extreme Gear riders the world has to offer, namely Jet the Hawk. It would appear that Sonic has a natural talent for Extreme Gear riding, as he quickly grasped the controls on his first try and can perform several advanced techniques, despite being self-taught. After the events of Sonic Free Riders, Sonic can be considered the best Extreme Gear rider in the world, as he was able to beat Metal Sonic, who at that point possessed all the data and skills of the world's best Extreme Gear riders, in a race.

In Sonic Generations, Sonic is shown to transfer his speed throughout various parts of his body (which may explain why he is able to boost in midair from a stationary position, negating certain physics), and on the second act of Planet Wisp, Sonic can even transfer to objects, as he can force a coal-carrying platform to speed up its movement by using his pure speed to make it go faster, and overtake other platforms (as well as crash into and break them).

Transformations
Throughout his adventures, Sonic has demonstrated the ability to utilize a number of different transformations (usually super transformations) to assist him in his toughest battles. This is usually done by using certain objects that possesses great power, or absorbing different varieties of energy. With these transformations, Sonic usually undergoes a physical alteration, gets his speed and strength increased and gains new abilities that match the theme of the transformation. While using these transformations, Sonic's personality and character usually remains the same, but some transformations has been known to affect his personality, giving him more darker traits.

Super Sonic
By using all seven Chaos Emeralds, Sonic can enter a Super State, transforming him into Super Sonic. This is by far Sonic's most frequently used transformation. In this state he can fly, is faster, stronger and nearly invincible. He does, however, need Rings to maintain this transformation or else he will revert to normal.

Hyper Sonic
In Sonic the Hedgehog 3 & Knuckles, Sonic also possesses an extended and more powerful form of Super Sonic, called Hyper Sonic, which he can assume with the seven Super Emeralds. This form basically shares the same powers and traits as Super Sonic, but they are all upgraded and are more powerful than Super Sonic's.

Darkspine Sonic
In Sonic and the Secret Rings, by harnessing the World Rings of rage, hatred, and sadness, Sonic can become Darkspine Sonic, a powerful form powered by his emotions at Shahra's death. In this state, Sonic can fly, has greater strength, unlimited use of the Soul Gauge powers and has pyrokinetic abilities that gives him fire-based attacks. Because of the intense emotions sealed inside the World Rings that Sonic used to transform, however, Sonic becomes slightly darker and more violent.

Excalibur Sonic
In Sonic and the Black Knight Sonic gains another transformation; Excalibur Sonic, by using the power of the Sacred Swords. This form grants him a strong golden armor with a red cape, the ability to fly, greater strength and the power to wield the legendary sword Excalibur.

Sonic the Werehog
In Sonic Unleashed, Sonic unwillingly gains the power to turn into a werewolf-like version of himself named Sonic the Werehog at night time by absorbing the energies from Dark Gaia. In this state, he loses his trademark speed, but still retains his lightning reflexes and agility. He also gains super strength, the ability to stretch his arms, and limited energy manipulation. While Sonic's strong will prevents him from going bonkers like other people affected by Dark Gaia, he does gain some minor feral behavior. He permanently lost this transformation after his battle with Dark Gaia.

Color Power Transformations


By harness different variants of Hyper-go-on from Wisps, Sonic can use certain Color Powers to transform into a specific form, such as a drill, a laser or even a fireball, with the Color Power depending on the type of Wisp. The forms invoked by the Color Powers include the Cyan Laser, Yellow Drill, Blue Cube, Green Hover, Pink Spikes, Purple Frenzy, Violet Void, Orange Rocket, Red Burst, Indigo Asteroid, Magenta Rhythm, Crimson Eagle, Ivory Lightning, Gray Quake, or Black Bomb. These transformations do only last for a few moments however, and requires more Hyper-go-on to be maintained.

Weaknesses
Sonic was originally incapable of swimming, which caused him to sink like a stone in water, probably mainly due to his presumed aquaphobia (or he just does not know how to swim) several later games (such as Sonic Free Riders) show him to have gained swimming capabilities. Although, if hitting the water while running, he can dash across the water's surface, completely bypassing the hazard (an exception being in Super Smash Bros. Brawl, in which all characters are able to swim, but he can only swim for a brief period of time before drowning). In most media, he is shown completely avoiding water. In Mario & Sonic at the Olympic Games and Mario & Sonic at the London 2012 Olympic Games, when Sonic competes in Aquatics events, he is the only character who wears a life preserver. However, in Super Smash Bros. Brawl, Sonic can swim without a life preserver, though he seems to be flopping like a fish when swimming, unlike the other characters. He also can swim in Dolphin Resort of Sonic Free Riders although it was implemented for a special gameplay of the race. Although an exception of Sonic's poor aquatic abilities is in Sonic the Hedgehog (1991), where he is capable of swallowing bubbles for extra breathing time in water. Further 2-D games allow for underwater breathing through the use of air bubbles. In most of the 3-D games, landing in water often results in an instant death and is, alongside bottomless pits, probably the most dangerous obstacle in the newer games. An interview with Yuji Naka states that, Sonic is scared of water because previously Yuji Naka thought that hedgehogs could not swim, but then he saw a picture of a hedgehog swimming but he could not get out of the water, so the hedgehog needed a tree to get out. This explains that Sonic can go in water, but he thinks he cannot get out and that no one would be able to help him, this is the reason he is scared of water. He can go underwater in Sonic Colors, but only for a limited time.

There is also reason to believe Sonic reacts terribly to being held captive and may find it mentally and perhaps even physically painful. He seems to act absurd if he does not run for a long time, which might mean that he is very much addicted to running, and gets frustrated when something is slow. An interview with Yuji Naka states that if Sonic does not get to sleep for eight hours during the night, it would spoil his running.

Relationships
This section is for Sonic's relationships in the games continuity only. For relationships specific to versions of the character in alternate continuities, see those versions' respective pages:


 * For the SatAM and Archie Comics continuities, see here.
 * For the Sonic the Comic continuity, see here.
 * For the Sonic X continuity, see here.
 * For the Adventures of Sonic the Hedgehog continuity, see here.
 * For the Sonic Underground continuity, see here.

In the games, Sonic has encountered many people, and thoughout his adventures, he has gotten many friends and foes alike. Sonic is well-known with his brotherly relationship with Tails, his friendly rivalry with Knuckles, and his fierce arch-rivalry with Shadow. Sonic's greatest enemy is Dr. Eggman, but Sonic comes across even greater enemies through his adventures.

Dr. Eggman
"Aw, I'm sorry! I didn't get that memo. I beat you every time!"

- Sonic's response to Eggman when Eggman says that he should had beaten him Dr. Eggman is Sonic's arch-nemesis and the two share a great mutual hatred to one another. Dr. Eggman and Sonic have been enemies even before Sonic met Tails. Eggman always tries to conquer the world, and Sonic always thwarts his plans. Sonic can be more frank or taunting towards Eggman in various games, and shows full confidence that he can spoil his plans no matter what. Sonic sometimes does not take Eggman's plans seriously and will almost always seize the opportunity to tease him. It is currently unknown how they became enemies, but in a scrapped storyline, it was said they were once friends.

Dr. Eggman's real name is Ivo Robotnik. In Sonic Adventure, however, when Sonic finally encounters Eggman, he teasingly says, "Hey look! A giant talking egg!" Robotnik tells him to stop fooling around, to which Sonic replies, "Whatever you say, Eggman!" After that, Sonic has been constantly calling him Eggman so much, even his friends started calling him Eggman. Even Robotnik refers to himself as Eggman and does not bother when anybody else calls him "Robotnik". It is stated by Yuji Naka that Sonic uses the nickname "Eggman" affectionately.

Sonic also seems to fall for Eggman's tricks, as shown in Sonic Unleashed, when he fell for the doctor's trap and was transformed into a Werehog. However, Eggman's plan for turning Sonic into a Werehog was unintentional.

In Sonic Adventure 2 and Shadow the Hedgehog, Dr. Eggman seems to take Sonic's side to fight Biolizard or Black Doom (mainly because these enemies are worse than Sonic, and the worst that Sonic would do is humiliate him).

In Sonic Colors, Sonic often outsmarts Eggman with his jokes and sarcasm. This is shown in the scene when Eggman was constantly trying to pull off puns about his amusement park. When Eggman comes up with a clever pun before the final boss fight, Sonic embarrassed him by saying, "I know you're trying to be clever with this whole amusement park pun thing, but it's just coming off lame! Just say you're gonna destroy us and stop embarrassing yourself!"

Miles "Tails" Prower
Tails is Sonic's best friend and sidekick. The two have been together since Sonic the Hedgehog 2, in which the two first meet. They have been best friends for so long that they share a brotherly relationship.

Sonic first met Tails on Westside Island, when Sonic decided to explore the area. During one of Sonic's runs, Tails saw Sonic and witnessed him running at high speeds. The young Tails was impressed by this and began to follow him. Sonic soon realized that the young fox was following him, but allowed him to do so, since he was impressed by how Tails could keep up. Still, Sonic remained uninterested in his new follower. All of this changed, however, when Dr. Robotnik began his attack on the island. After being awakened from his nap by the attack and seeing to Tails' safety, Sonic headed out to stop Robotnik, but he could not prevent Tails from joining him and following him all the way.

During the course of their adventure, however, Tails proved to be a great assistance to Sonic, such as by repairing his plane, the Tornado. As such, Sonic came to have great respect for Tails, and the two of them began to form a friendship. At the end of their adventure, when Tails saved Sonic from his fall from the Death Egg, Sonic had built a strong bond with the young fox, and the two became close friends.

After this adventure, Sonic and Tails were always there to help each other. Their friendship grew and grew until they had a more brotherly relationship. Tails often invents machines for Sonic and also made him three Extreme Gears. In Sonic Advance 3, they are known as the "Unbreakable Bond" when they team up. In Sonic Rivals 2, it is shown that Sonic trains Tails to learn how to run and fight in their free time. Whenever Sonic has an adventure to explore, he always comes to Tails and asks him to come along, and Tails is always ready to help.

Sonic is shown to care greatly about Tails. In the opening of Sonic Riders, Tails was hurt by Storm during a race causing him to be pushed back, even though Sonic was leading first place in the race, he went all the way back to help Tails balance and raced on Tails' side till the end of the race. Tails was also very persistent in making Sonic's Extreme Gear the best Extreme Gear in the world because Wave had insulted Sonic's Blue Star.

In Sonic Colors, they are seen together throughout the whole game. It is noticeable that Sonic and Tails seem to be a lot more friendly and act like saving the day is an everyday job, which has not been seen in games for a while. Tails' esteem about Sonic's heroics seems to have dwindled, seeing as Tails cares more about inventing than Sonic's heroic deeds, not even noticing when Sonic does something. When Tails was mind-controlled by Dr. Eggman, Sonic refused to fight Tails and instead tried talking to Tails. Before the final battle of the game, Sonic pushes Tails to Eggman's elevator for his safety.

In Sonic Lost World, when Sonic realised Tails was almost shot from the badniks under the control of the Deadly Six, Sonic came to his aid, carried him and took off with him rather than continuing to fight the badniks and potentially see Tails harmed severely. Later, the pair's friendship started to become strained when they form an alliance with Eggman, as Tails got mad and believed Sonic was more trusting of Eggman, his own nemesis, than him. It became further strained when Sonic got cross with Tails for putting Cubot's head on a battle mech, which caused Cubot to almost attack Tails. Tails later saved Sonic from getting captured by the Deadly Six, but got captured himself. Sonic, feeling guilty for getting Tails captured because of his recklessnes, made it his top priority to save Tails, even going as far as to threaten Zor and Zavok. He became horrified when he learned that the Zeti were going to turn Tails into a robot, and was visibly dishearted when they seemingly succeed, but was quickly overjoyed when he learned that Tails never got turned into a robot. At the end of the game, Sonic apologizes for doubting Tails, and Tails forgave him, mending their brotherly bond.

Amy Rose
Amy and Sonic first met when Sonic had to save her from Metal Sonic in Sonic CD. After that Amy has been madly in love with Sonic, and chases him down wherever he goes; however, Sonic seems annoyed by her affection and disturbed by her over the top displays, and tries to run away or avoid her when she goes overboard. However, when Amy is in trouble, Sonic is always present to save her and they are shown to be good friends. Sonic running away from Amy's affections has become a very frequent gag eversince her first debut. Sonic seems to fear Amy whenever she gets angry and runs away fearfully when she pulls out her Piko Piko Hammer. It has been stated in the Sonic Heroes manual that he may not dislike her as much as it seems.

In Sonic Adventure 2 when Sonic was in jail and asked Amy to help him get out, she jokingly replies that she'll help him if he'd marry her, to which Sonic refuses. Sonic finds her weird or a pain to him at times such as in Sonic Adventure when Amy wanted to go out with Sonic in Twinkle Park. Out of embarrassment and exasperation he says to himself, "I give up! She's so weird!" or "Ugh, that girl is such a pain!", though he follows after her regardless of complaint.

In Sonic Unleashed, Amy encounters Sonic in his Werehog form, but does not recognize him and runs off to continue searching for him. Chip then accidentally hurts Sonic's feelings by reminding him that people cannot recognize him because of his scary new look. Sonic walks away downheaded as Chip tries to apologize and make him feel better. After Sonic saves her from a pack of Dark Gaia creatures who possessed a group of people to have a night party in the streets, he runs away from her. Amy took in a glimpse of him, and was left wondering if that was Sonic. When Amy asks Sonic to go out with her after he saves the world, the player can choose whether Sonic agrees or not.

In Sonic Free Riders, Sonic seems to be more annoyed with Amy when she constantly tells him that they have to go out and even tells him that he should take it easy on her in the race. When Team Sonic wins against Team Rose, Amy becomes angry at Sonic and demands he takes her on a date to make it up with her, Sonic replies "Why would I owe you a date for winning a race?". In the end of the Team Rose story, Amy forces Sonic to go out with her because she won, but Sonic, not wanting to go runs away from her.

In Sonic Generations Amy is excited to attend Sonic's birthday. However, Sonic keeps Amy away from getting too close to him by placing his hand over her face while talking to Tails. When Classic Sonic rescues Amy, she mistakes him for Modern Sonic and questioned on how he looks so young, leaving him confused, whereas when Modern Sonic saves Amy, Amy tells Sonic that she was afraid that she will never "be able to flirt him again", leaving Sonic exasperated.

Metal Sonic
Sonic and Metal Sonic have a violent rival/enemy relationship. Eggman created Metal Sonic in order to defeat the real Sonic, knowing that something as powerful as Sonic would be able to succeed. Since Metal Sonic contains most of Sonic's abilities, they are almost always fighting with each other.

Metal Sonic has a strong dislike towards Sonic, always trying to prove that he is better then him in every way, and even calls Sonic "My loathsome copy", as well as believing that he is the real Sonic. In Sonic Heroes, when Metal Sonic took control of Eggman's fleet, his intentions were to kill Sonic and then build a robot empire, but Sonic and his allies ended up defeating him, and afterwards Metal Sonic asked Sonic why he could not beat him and shut down. Also, in this game, Metal Sonic's real emotions towards Sonic were released. In Sonic's view, Metal Sonic is the worst creation Dr. Eggman has ever made, due to how the robotic hedgehog always causes a lot of trouble for him.

Metal Sonic's hatred for Sonic went on after that, even after Eggman restored him to his robotic slave. He later broke free from Dr. Eggman's control once again in Sonic Free Riders in order to face Sonic, this time in Extreme Gear, but he was defeated once more in a one-on-one race.

Knuckles the Echidna


Another of Sonic's close friends is his relationship with Knuckles. Ever since Knuckles' introduction, there was recurring and unfinished battle between Sonic and Knuckles. Because of their differences and morals, the two are constantly getting into a crossroads, which then become outright fisticuffs. However, they finish the battle tied, or something serves to interrupt the battle before its end. The battle has appeared in the games. It occurs in many games featuring Knuckles since his debut in Sonic 3. With Sonic's speed paralleling Knuckles' strength in every way, their fights are always climactic.



It should also be noted that in various games, Sonic teases Knuckles whenever Knuckles falls for Eggman's tricks by making a pun out of his name; "Knuckle-head". In Sonic Rivals 2 Sonic teases Knuckles when he sees Knuckles and Rouge together by saying, "Well look who it is... Knuckles and Rouge! You two on a date or something?".

The rivalry has all but disappeared in some continuities, and in others, it is a sort of game between the two, actually serving as the plot for the game Sonic Rivals 2, when Knuckles tells Sonic that he needs to find Eggman, Sonic taunts him by saying that he'll beat Knuckles to Eggman, causing them to fight.

Overall, they are great friends and make a great team. Next to Tails, Knuckles is also Sonic's best friend.

In the DS version of Sonic Colors when Sonic heard that Rocket Wisps are easy to anger and easy to be happy, Sonic compares them to Knuckles. When Sonic meets Knuckles at Starlight Carnival. Sonic and Knuckles still retain their rivalry but do not really argue. Instead, Sonic tries consoling Knuckles in getting angry when he was not accepting on getting tricked by Eggman, Knuckles keeps on yelling that he did not get tricked to which Sonic replies, "Alright! Alright! You didn't!". Tails also commented that Sonic and Knuckles are "funny" together.

In Sonic Generations, he was among the many characters that attended Sonic's birthday party. If Classic Sonic rescues him, Knuckles mistook him for Modern Sonic and asks if he gained weight. If Modern Sonic rescues him, Knuckles will thank him but rebutted that he did not really need the help. Sonic would look at him weird, but then he gives him thumbs-up with a smile.

Shadow the Hedgehog
Shadow the Hedgehog is Sonic's arch-rival. They look almost identical (to the extent that many characters got them confused in Sonic Adventure 2), and they share almost every ability they have, including Chaos Control. Since they first met they have fought, argued, and tried to kill each other every time they cross paths. Anything considered competitive is suitable for their bitter arch-rivalry.

Their moral differences are as far apart as black and white, always causing the two of them to clash. Sonic has a joyful, carefree attitude that looks for fun adventures, while Shadow has a dark, merciless edge and is known to be the most violent character in the series. Sonic has few limitations on his goals, but Shadow is willing to do whatever it takes to get what he wants, never caring about who or what it effects. Nevertheless, they do not care what each thinks of the other's views, and see them as yet another reason to fight each other.

Out of all the rivals Sonic faces, Shadow is the one whom he struggles most with. Shown in all the clashes between the two, they are nearly equally strong or as strong as the other, with both sides proving to be neither lacking in any category that separates them from skill in their respective prowess. It is shown that while Sonic is becoming faster and more honed than Shadow, Shadow is getting stronger and more destructive than Sonic. This has only increased the intensity of their arch-rivalry. They have an unshakable need to showcase their growth and improvement for each and every encounter they have.

Despite their conflicting differences, Sonic has been very impressed by Shadow's victories in battle. Sonic went so far as to say that Shadow defeating Black Doom and destroying the Black Comet was "sweet". Though Sonic and Shadow rarely tolerate each other, Sonic does respect Shadow to a certain degree. This respect is rarely apparent though, because he and Shadow fight constantly.

Blaze the Cat
Blaze was designed as a character who was equivalent yet an alternate version of Sonic's character in her debut in the Sonic Rush series. Both have the same duty and similar skill, yet have very different backstories and personalities which is later shown to mix very well in Sonic Rush Adventure as their friendship and mutual understanding grows. There is a contrast between the two protagonists - Sonic being inwardly the free and adventurous, yet outwardly level-headed and cool one, whereas Blaze is the outwardly stoic and blunt, yet inwardly highly emotional one.

Sonic and Blaze first met when she was searching for the Sol Emeralds in Sonic's world in Sonic Rush. At first, Blaze did not care who Sonic was as Cream and a few others told her to seek his help, but she claims that she does not need anyone to help her. Sonic was quite interested in Blaze to the point where he decided to find her, finding her suspicious. After meeting her and seeing that she is Cream's friend, Sonic finds out that Blaze is also stopping the space-time continuum from tearing and therefore is not the enemy. Though Sonic only intended to help her, Blaze started to attack him, selfishly not willing to accept his help and berated him during the battle.

Their battle is a draw where Sonic, who kindly asked her if she can stand up and tells she put up a pretty good fight. Blaze realizes by Sonic's advice that accepting help from others will benefit her duty and the two become friends and combat partners. When Blaze was called by Eggman to rescue Cream, who was kidnapped by confronting Eggman alone, Sonic willingly trusts her to bring Cream back safely while she trusts him and Tails to confront Eggman Nega.

Later, when Dr. Eggman and Eggman Nega team up, Blaze starts to lose faith in herself, but Sonic cheers her up, as soon as she regains faith and learns the power of true friendship she was able to use the power of the Sol Emeralds and the two transform. After their battle, they say their goodbyes, where Blaze thanks Sonic and the two made a promise that they will meet again as the two held hands until they were separated.

In their next meeting, Sonic ends up in Blaze's dimension, along with Tails, where they work together as allies to stop the Doctors' plans. After defeating them, Blaze tells Sonic that it is possible that the Emeralds brought him to her world, implying a connection between them and the Emeralds. Sonic, confused for a second, smiled and said, "Well, you never know!". The two then shake hands, positive that they'll meet again.

Sonic seems to acknowledge Blaze's skills, seeing as how she is one of the few people who is able to equally match him and possibly have the potential to defeat him in direct combat, and he holds a great deal of respect for her. Blaze, in turn, once said that she "bows before his skills". Blaze also seems to rely on Sonic the most and has a certain respect for him to the point where she considers him as her most trusted ally and friend. In Sonic Rush Adventure the two are shown to work very well and have a good chemistry during combat.

Silver the Hedgehog
Sonic and Silver first met during the events of Sonic the Hedgehog (2006). The two were enemies at first because Silver had traveled though time and was intending to kill Sonic believing that he was responsible for destroying his time by releasing Iblis onto the world and was bent on saving the future. But Silver befriended Sonic when he discovered that Sonic was not the Iblis trigger and that Mephiles the Dark had lied to him. The two worked together to save Princess Elise and when Sonic was killed by Mephiles, Silver realized that they could save Sonic with the power of the Chaos Emeralds. Afterwards Silver teamed up with Sonic and Shadow to defeat Solaris. But since the events of the game were erased from history, Sonic and Silver never met. They do not actually meet until Sonic Rivals where Silver has traveled to the past to bring Eggman Nega back to the future, but Silver seems to be more competitive to Sonic as they raced each other see who would get to Eggman Nega first but later they teamed up with each other at the end to defeat Eggman Nega and also in Sonic Rivals 2 to defeat the Ifrit. It appears that Sonic and Silver do not remember each other from their past adventure since the events of Sonic '06 were erased.

Silver seems to have a bit of a disliking towards Sonic mostly because he thinks that he is cheeky and foolish, much the same how Shadow thinks of Sonic at times. Silver's attitude tends to annoy Sonic at times as well as seen in Sonic Rivals when he says, "Yo Silver, you've got an attitude". But they will work together and lay aside their differences whenever the time is right. An example is in Sonic Colors after Silver challenges Sonic to a mission, he asks if he needs any help. In Sonic Generations Silver is the only boss-fight who wants a friendly fight.

Jet the Hawk
Sonic and Jet have been rivals ever since they met, and their relationship is deeply based on their competitive nature and their distinct respect for one another. When meeting with each other for the first time, Sonic managed to pass by Jet while riding Extreme Gear while chasing after him, only for the hawk to blow him off Storm's Type-S and getting away. However, Sonic was left rather impressed by Jet's skills and instantly recognized him as a new rival for him to face.

During Eggman's first EX World Grand Prix, Sonic was not exactly fond of Jet due to the hawk constantly berating his attempts at mastering Extreme Gear riding, and would get rather angry at Jet's insults at his speed. While thinking the hawk was rather full of himself, Sonic still recognized Jet's skills as an Extreme Gear rider and held a determined, albeit one-sided at the time, rivalry with him. Whenever he was around him, Sonic would have a professional, yet competitive, attitude around Jet.

In finals of the EX World Grand Prix, when Sonic lost to Jet due to Wave planting a bomb on his Blue Star, Sonic was left especially frustrated at Jet's insults, which only served to increase the tension he held towards Jet. Eventually, however, Sonic finally settled his own dispute with Jet when he managed to beat him in a race to Eggman at Babylon Garden, proving to Jet that he was still the fastest thing alive. At the end of Sonic Riders, Sonic had a more friendly relationship with Jet, as each of them had gotten respect for one another, and promised each other to compete once again, though they both still remained firm rivals.

Since defeating Jet, Sonic has hold a more relaxed and friendly attitude towards Jet, taking his insults and rash determination to beat in a race him in stride. Nevertheless, Sonic's rivalry with Jet is remains as strong as ever, and he will gladly, if given the right opportunity, face him in a race, though he these days does it more for the excitement and fun of going up against Jet. However, even when determined to beat Jet, Sonic does not wish to have unfair advantages when winning against Jet, and is willing to give Jet both the chance to prove himself and face him at his best, such as in Sonic Free Riders, where Sonic would give Jet a rematch after discovering he had mechanical troubles with his Type-J. Despite how many times they face each other, Sonic always look forward to his next rematch with Jet.

Himself
The Sonics of the Modern and Classic eras meet each other after being thrown back in time in Sonic Generations. At first none of them recognize each other as they both mistake the see-through glass for a mirror until Classic (Past) Sonic runs towards the door leading to Eggman while Modern (Present) Sonic realizes it was another Sonic and gets shut out of the battle. At the White Space, the Sonics team up and race through time to fix space and save the world. Their teamwork is unparalled as they act in perfect sync and share the same gestures simultaneously in every scene; this is due to them being the same person.

To Modern Sonic, Classic Sonic is sort of like an awesome younger brother to him, someone who is hyped up on simply running and rolling around just simply enjoying life to the fullest. He enjoys seeing what he used to be like, being limited to the few tricks he had but made the most of them as he has experienced and developed them before when he was him before.

To Classic Sonic, Modern Sonic is somewhat like a cool older brother to him, someone who is stronger and faster than him, able to pull off the impossible and acts as a role model. He's very eager to learn what he will be like, gaining more experince and mastering all of the new tricks that he will develop when he becomes him, such as at the end of Sonic Generations where he attempts to do a Sonic Boost, but failed as it was his first attempt at the move, but nonetheless, his older counterpart encouraged him.

Friends/Allies

 * Miles "Tails" Prower (best friend, close as brothers)
 * Amy Rose (self-proclaimed girlfriend, love interest)
 * Knuckles the Echidna (best friend and rival)
 * Vector the Crocodile
 * Espio the Chameleon
 * Charmy Bee
 * Big the Cat
 * Shadow the Hedgehog (arch-rival)
 * Rouge the Bat
 * Cream the Rabbit
 * Cheese the Chao
 * Vanilla the Rabbit
 * E-123 Omega
 * Blaze the Cat (close friend and partner in combat)
 * Silver the Hedgehog (friendly rival)
 * Shade the Echidna
 * Chip (great friend)
 * Yacker
 * Wisps

Rivals

 * Shadow the Hedgehog (arch-rival)
 * Knuckles the Echidna (old rival)
 * Silver the Hedgehog
 * Jet the Hawk (rival in speed)
 * Mario (friendly rival)
 * Rouge the Bat (friendly rival)

Enemies

 * Doctor Eggman (arch-enemy)
 * Metal Sonic/Metal Overlord (robotic doppelgänger)
 * Dr. Eggman Nega
 * Shadow the Hedgehog (sometimes)
 * Silver Sonic
 * Mecha Sonic
 * Fang the Sniper
 * Pir'Oth Ix
 * Shade the Echidna (former)
 * Chaos/Perfect Chaos (former)
 * Biolizard/Finalhazard
 * Solaris
 * Dark Gaia
 * King Arthur
 * Dark Queen
 * Erazor Djinn/Alf Layla wa-Layla
 * Nega-Mother Wisp
 * The Deadly Six

Reception and legacy
As Sega's mascot and one of the key reasons for the company's success during the 16-bit era of consoles, Sonic is one of the most recognizable video game characters in the world. In 1996, Sonic was the first video game character to be seen in a Rose Parade. Sonic is also the first of two video game characters to have a balloon in Macy's Thanksgiving Day Parade (the other being Pikachu).

Sonic was one of the three game characters inducted on the inaugural Walk of Game class in 2005, along with rival Mario and Link. One of a class of genes involved in fruit fly embryonic development, called hedgehog genes, has been named "sonic hedgehog" after the character.

As Sega's mascot, Sonic has also been used as a symbol for the company's various sponsorships. Between 1993 and 1997, Sega sponsored the JEF United Ichihara Chiba football team, during which period Sonic appeared in the team's uniform. During the 1993 Formula One championship, Sega sponsored the Williams Grand Prix team, which won the Constructors' Championship that year, as well as the team's lead driver, Alain Prost, winning the Drivers' Championship. Sonic was featured in the cars, helmets, and rival McLaren used to paint a squashed hedgehog after winning races over Williams. The 1993 European Grand Prix featured a Sonic balloon and Sonic billboards, and the race's trophy was in the shape of a hedgehog. Sonic also appears on some versions of the willow video store logo. Sonic is more recognizable for people than Mickey Mouse according to a poll.

On the 21 October 2008, Sonic was voted the most popular video game character in the UK with a 24% vote. His old rival Mario came second with 21% of the vote.

Cameos/popularity
Sonic has proven to be an extremely popular character. After the first game, Sonic the Hedgehog (1991) came out, Sonic became a well-known and very familiar character, even at a time beating Mickey Mouse. After having been around only 2 years, he had already surpassed Nintendo's Mario in popularity according to a June 1993 Q-Survey in Gameplayers magazine. As a result of this popularity, he has been referred to in various parts of culture. Sonic recently made cameos in the Disney animated feature, Wreck-It Ralph.

Voice acting
The earliest voice of Sonic was Takeshi Kusao in the arcade game SegaSonic the Hedgehog.

In Sonic the Hedgehog CD, Sonic actually had a few voice clips, who was voiced by Keiko Utoku at the time in which he would say, "I'm outta here!" if the player stood still for 3 minutes, and "Yes!" if the player obtained a 1-up. This was also the first and only game where Sonic had been voiced by a female actor.

The original American voice actor was Jaleel White in Adventures of Sonic the Hedgehog, Sonic the Hedgehog (SatAM) and Sonic Underground. In Sonic the Hedgehog: The Movie, Sonic was voiced by Martin Burke.

Starting with the 1998 game Sonic Adventure, all of Sonic's video games feature voice acting. Sonic was played by Junichi Kanemaru, who later went on to play Sonic in the Japanese version of Sonic X. Ryan Drummond performed the role of Sonic in Sonic Adventure and continued to play the role for several games. Information taken from the credits of both Sonic Adventure games, the Sonic Advance series, and Sonic Heroes. 4Kids Entertainment decided not to use Drummond's voice in their English dub of Sonic X, instead choosing their own Jason Griffith. Despite this, Drummond continued to provide the voice of Sonic in the series until 2004, when Sega replaced all their Sonic voice actors with their 4Kids counterparts, in order to keep his voice the same in all media forms. Effectively, this meant that beginning with Shadow the Hedgehog and Sonic Rush, Jason Griffith became the official game voice actor for Sonic the Hedgehog and Shadow the Hedgehog (and Jet the Hawk in Sonic Riders). This has been a controversial decision among fans of the Sonic Adventure voice cast.

As from 2010, SEGA had announced that they have changed the whole cast of the active characters of the franchise (sans Eggman), replacing Griffith with Roger Craig Smith.

Memorable Quotes

 * "I'm Sonic. Sonic the Hedgehog." - Sonic introducing himself.
 * "Long time no see!" - Sonic greeting people in a few games.
 * "I'm outta here!" - Sonic when the player waits for too long in Sonic the Hedgehog CD.
 * "Aw, yeah! This is happenin'!" - Sonic enjoying a run on building rooftops in his intro of Sonic Adventure.
 * "It won't change how he feels inside, will it? His heart will still remain in turmoil and his anger just won't vanish!" - Sonic claiming that sealing Chaos in the Master Emerald will not change anything, in Sonic Adventure.
 * "Hey, I'll play with you some other time!" - Sonic in Sonic Adventure after defeating a boss.
 * "Talk about low budget flights, no food or movies? I'm outta here! I like running better." - During the intro to the Hero Story in Sonic Adventure 2.
 * "Say something! You fake hedgehog!" - To Shadow when first encountering him Sonic Adventure 2.
 * "Too easy. Piece of cake!" - Sonic getting a B Rank in Sonic Adventure 2 and winning a match in Super Smash Bros. Brawl.
 * "You've turned into a big time villain, doctor!" Sonic to Eggman when passing the fake Emerald in the ARK in Sonic Adventure 2.
 * "Let's head back to the planet that's as cool and blue as me!" - After defeating the Finalhazard and talking with Amy in Sonic Adventure 2.
 * "Let's blast through with Sonic speed!" - Selecting Team Sonic in Sonic Heroes.
 * "Marriage? No way!"- In Sonic Heroes after defeating Team Rose in response to Amy's marriage proposals.
 * "Time to crack that Eggman wide open... Yeah, let's party." - Sonic in the Team Sonic intro from Sonic Heroes.
 * "Shoot! Not my day..." - Sonic getting an E-Rank in Sonic Heroes or getting a 1-Star rank in Sonic and the Black Knight.
 * "Ready anytime!" - When Sonic gets a Team Blast for Team Sonic in Sonic Heroes.
 * "Alright. Let's get ready to do this. We'll show that creep the real super power of teamwork!" - Sonic and friends about to confront Metal Madness in Sonic Heroes.
 * "Anytime you want a rematch, just let me know! I'll be waiting!" - Sonic challenging Metal Sonic to a future match in Sonic Heroes, later to be done in Sonic Free Riders.
 * "Let's do it!" - Sonic in the beginning of the levels in Sonic Rush and Sonic Rush Adventure.
 * "You need to be true to yourself!" - Sonic talking to Blaze in Sonic Rush.
 * "Looks like the party's getting started! Time to rock and roll!" - Sonic about to go to a stage with Shadow in Shadow the Hedgehog.
 * "Personally, I wouldn't be caught dead using one of those things!" - Sonic saying that he would never use a firearm in Shadow the Hedgehog.
 * "You up for this Shadow?" - Sonic asking if Shadow's up to fight a massive army of Black Arms when they were going up to the Space Colony ARK in Shadow the Hedgehog.
 * "Shadow, don't you remember? We once raced each other here." - Sonic asking Shadow if he remembers their race from Sonic Adventure 2 in Shadow the Hedgehog.
 * "What, that lame robot copy of yours again? You really need to get a hold of better toys!"- Sonic when Eggman (who is actually Eggman Nega) dispatches Metal Sonic to race against Sonic for the second time in Sonic Rivals.
 * "A copy is still a copy! It will never top the original."- Sonic when Eggman (who is actually Eggman Nega) dispatches Metal Sonic to defeat him in Sonic Rivals.
 * "My... That's a pretty snazzy performance there."- Sonic in his opening cutscene for Sonic the Hedgehog (2006) and after winning a race in Sonic and Sega All-Stars Racing.
 * "Nothing starts until you take action. If you've got time to worry, run!" - Sonic talking to Elise in Sonic the Hedgehog (2006).
 * "You're too slow!" - One of Sonic's taunts in Super Smash Bros. Brawl.
 * "Sonic's the name, speed's my game!" - After winning a match in Super Smash Bros. Brawl.
 * "Come on, step it up!" - Sonic taunting in Super Smash Bros. Brawl.
 * "Finally! Something interesting!" - Sonic in the teaser trailer for Sonic and the Secret Rings and after hearing the Babylon Guardian roared in Sonic Riders.
 * "And enough of that 'rat' stuff! Seriously! I'm a hedgehog! HEDGE-HOG!" - After Erazor Djinn calls Sonic a rat in Sonic and the Secret Rings.
 * "I told you, I'm not a rat! I'm a hedgehog!" - Sonic when Erazor "fulfills" Sonic's final wish of trapping Erazor in his lamp forever in Sonic and the Secret Rings.
 * "Yeah, this is the real me. Pretty cool huh?" - Sonic telling Chip that this is what he usually looks like in Sonic Unleashed.
 * "Yo, Eggman. Thanks for that little skydiving adventure the other day!" - Sonic after saving the people of the village in Mazuri.
 * "Do I need a reason to want to help out a friend?" - Sonic after discovering that Chip is actually Light Gaia, who believes that defeating Dark Gaia is not Sonic's responsibility.
 * "Time for the big finale!" - Sonic in the final battle against Dark Gaia in Sonic Unleashed.
 * "Hey! Hold up a minute. Girls hate guys who rush them, Jet." - Sonic coming to Amy's aid after Jet accuses her of stealing an Ark of the Cosmos in Sonic Riders: Zero Gravity.
 * "Alright! Bring it on!" - Sonic when starting a race in Sonic Riders: Zero Gravity.
 * "I'm Sonic the Hedgehog. I have no master, except the wind that blows free." - Sonic introducing himself to Sir Percival in Sonic and the Black Knight.
 * "Let's just say that whim is my other master." - Sonic after saving Sir Percival, following their fight in Sonic and the Black Knight.
 * "A knight... never... flees his foe... right?" - Sonic restating Caliburn's words to the knights of the round table, when he refuses to run away from Merlina during their fight in Sonic and the Black Knight.
 * "It was... never about chivalry for me... I just gotta do what I gotta do, that's all!" - Sonic when badly beaten by the Dark Queen in Sonic and the Black Knight.
 * "Aw man!" - Sonic when getting shocked by the electric bolts of King Arthur's sword (Boss Battle) in Sonic and the Black Knight.
 * "It's all about speed!" - Sonic if he comes in first place in Mario & Sonic at the Olympic Games.
 * "Aw man, I could've done better..." - Sonic if he comes in 4th place or lower in Mario & Sonic at the Olympic Games.
 * "Phew! Just made it!" - Sonic when coming in 2nd or below in a circuit in Mario & Sonic at the Olympic Games
 * "Faster than the speed of sound!" - Sonic before starting an event in Mario & Sonic at the Olympic Winter Games.
 * "Wait, we're going up against them? Seriously?" - Sonic after he found out he had to go up against Team Rose in Sonic Free Riders.
 * "Because Eggman plus secretly built amusement park equals evil plot for us to foil." - Sonic talking to Tails at the beginning of the story in Sonic Colors.
 * "I did a little shopping, grabbed a bite to eat, and trashed a giant killer robot." - When Tails was wondering where Sonic was in Sonic Colors.
 * "BALDY NOSEHAIR!? That is the best thing I've heard all day! I gotta remember that one!" - Sonic laughing when Tails told him that the Wisps call Eggman "Baldy Nosehair" in Sonic Colors.
 * "Eggman! I AM going to save this planet, and I AM going to free these aliens. No copyright law in the universe is going to stop me!" - Sonic before fighting the boss on Planet Wisp in Sonic Colors.
 * "A hedgehog's gotta do what a hedgehog's gotta do." - Sonic tells Tails he did what he had to in order to defeat Eggman and outrun the black hole that enveloped the theme park in Sonic Colors.
 * "Look I know you're trying to be clever with this whole amusment park pun thing, but it's just coming off lame. So just say you're going to destroy us and stop embarrasing yourself."  - Sonic telling Eggman to give it a rest with his lame speeches.
 * "Thanks. But I had a little help on the last part..." - Sonic telling Tails about how the Wisps saved his life at the end of Sonic Colors.
 * "Well, I can jog around the planet again if you want." - Sonic to Tails after knowing about his suprise birthday party in the 3DS version of Sonic Generations.
 * "An adventure's no fun if it's too easy" - To Classic Tails when Tails says they have their work cut out for them in Sonic Generations.
 * "Destroy me? You and what mustache? I beat you all the time by myself, and now there's two of me!" - to both Dr. Eggman and Dr. Robotnik before the first half of the boss fight with the Time Eater in Sonic Generations; he's referring to the fact there's both Modern and Classic Sonic.
 * "Dude, sweet! And you're only going to get better!" - Sonic complienting his Classic who attempted to perform the boost and after winning a race in Sonic & All-Stars Racing Transformed.
 * "Hey Sonic! Enjoy your future. It's going to be great!" - Sonic's farewell to his Classic self when he is going to return to his original timeline, at the ending of Sonic Generations.
 * "Now I'm serious!" - Sonic unleashing his All-Star Move in Sonic & SEGA All-Stars Racing.
 * "Drop the critters, Eggman!" Sonic at the opening of Sonic Lost World.
 * "Whatever! Since when is it a mistake to take your toys away?" - Sonic after Eggman tells him that kicking the Cacophonic Conch out of his hands was a mistake in Sonic Lost World.
 * "I hate to run away from a fight, Tails, but I don't want to see you get fried." - Sonic coming to Tails' side after seeing Tails almost being shot by the badniks under the Deadly Six's control in Sonic Lost World.
 * "One word of helpful advice: diet and exercise." Sonic encountering Zomom for the first time in Sonic Lost World.

Solo Themes

 * In Sonic CD, Sonic's theme in the American version is "Sonic Boom." In the Japanese and Europe versions, his theme is "Sonic - You Can Do Anything."
 * In Sonic Adventure, Sonic's theme is "It Doesn't Matter."
 * Also, in Sonic Adventure 2, the City Escape stage has lyrics to the music, which refer to Sonic in the line "Rollin' around at the speed of sound".
 * In Sonic Adventure 2, Sonic's theme is a a faster-paced, alternative rock remix of "It Doesn't Matter."
 * In Sonic the Hedgehog (2006), the main theme "His World" relates to Sonic with lyrics like "and straps on his shoes" that refer to Sonic because of his iconic shoes and "'cause he's the best there ever was, haven't ya heard the news" because he is often referred to as a savior to mankind and he is known by many in his world.
 * In Sonic and the Black Knight the main theme "Knight of the Wind" is probably referring to Sonic, for Caliburn eventually calls him so.
 * In Sonic Unleashed, Sonic's theme is "Endless Possibility," which describes life from his point of view.
 * In Sonic Colors, his theme is "Reach For The Stars" describing from his point of view on his new adventure.

Shared Themes

 * In Sonic Adventure 2, he shares the theme "Live and Learn" with Shadow.
 * In Sonic Heroes, Team Sonic's (Sonic, Tails and Knuckles) theme is "We Can," and refers to Sonic in the lines "Look out down below, Sonic is on the go" and "Sonic's in the lead, giving us greater speed!"
 * In Sonic Rush, Sonic and Blaze's theme "Raisin' Me Up" is about how Sonic helped Blaze in her time of need and taught her value of friendship which is played after they defeated the final boss.
 * In Sonic Riders, Sonic's team theme, shared with Tails and Knuckles, is an instrumental called "High Flying Groove."
 * In Sonic Riders: Zero Gravity, Team Sonic's theme song is "Un-Gravitify."
 * In Sonic Unleashed, Sonic, Chip, and possibly Tails's shared theme "Dear My Friend" is played during the credits of the game.
 * In Sonic Free Riders, the theme "Free" could have some connection with both Sonic and his Extreme Gear rival Jet.

Trivia

 * There is a genome named Sonic hedgehog.
 * In 1993, Sonic was the first video game character to appear in the Macy's Thanksgiving Day Parade (the second was Pikachu from the Pokémon franchise in 2001). Sonic had reappeared in 2011 as the lead of the parade, commemorating his 20th anniversary. He continues to be in the parade to this day.
 * If left alone for too long in the first Sonic game, Sonic will become impatient and tap his foot on the ground until the player continues.
 * In Sonic CD, after standing still for three minutes, he will say "I'm outta here" and jump off the screen, after which the "GAME OVER" screen will appear.
 * Sonic Adventure 2, Sonic Riders, Sonic Riders: Zero Gravity, Sonic Free Riders and Sonic Unleashed (while in Werehog form) are the only games in which Sonic wears different shoes.
 * Sonic's first appearance in a game was not in Sonic the Hedgehog, but in Rad Mobile as a cameo.
 * When Sonic closes his eyes in every classic Sonic game, Sonic Adventure, Sonic Adventure 2 and all three Sonic Advance games, his eyelids are the same color as his arms and muzzle. After that, his eyelids were changed to blue. However, in one commercial, his eyelids were not blue, and in a Japanese commercial for a game, he had no eyelids at all (he blinks twice in the commercial, but his eyes are still open). This is alluded to in Sonic Generations, as Modern Sonic has blue eyelids while Classic Sonic has flesh-colored eyelids.
 * Sonic's favorite food is chili dogs.
 * According to an interview on Sonic Central, Sonic does not know the whereabouts of Mighty the Armadillo, Ray the Flying Squirrel, Nack the Weasel, Bark the Polar Bear or Bean the Dynamite.
 * In Sonic Rush, if Sonic is tapped with the stylus during gameplay, he will clap, jump back and forth and continuously swing his arm clockwise, as if he is exercising.
 * Originally, Sonic was intended to have visible fangs in his Japanese artwork, though they were removed when he was given a more Americanized design for his US artwork in order to "soften him up" slightly. Even though he still possesses fangs, they are only visible when he opens his mouth (this is mainly noticeable in Dreamcast titles such as Sonic Adventure and Sonic Shuffle, but became less obvious after Sonic Adventure 2). Previously, his fangs were supposed to be visible even when his mouth was closed.
 * In some drawings, such as the official artwork for SegaWorld Sydney and a few animation cells, his arms are erroneously colored blue.
 * Sonic's age has always been difficult to pinpoint. A mistranslation in the original Japanese manual states that he is 10 years old. According to the Sonic Technical Files, he is 18, "but it's kinda hard to tell". Once Sonic Jam was released, his age appeared to be solidified at 16, but Sonic Channel had finalized it as 15. In of Sonic Generations, Sonic's birthday was held, suggesting he has aged a year, but nothing official has been said.
 * In the Japanese versions of the games, Sonic proves that he knows more English than any of the other characters, as he is the only one who speaks English many times in the games. This may be due to the fact that the English language is considered "cool" in Japan, and it therefore makes sense to have the "coolest" character speak many English lines, as well as his Japanese voice actor wanting him to.
 * Sonic is the first character to utilize the Chaos Emeralds, transforming into Super Sonic in Sonic the Hedgehog 2.
 * In the 2011 Guinness World Records Gamers Edition, Sonic placed 10th in the "Top 50 Video Game Characters Of All Time". His rival, Mario, placed first, and Shadow had placed 25th.
 * Every time Sonic appears in a band, he is the guitarist.
 * It is possible that Sonic is able to move faster than the speed of light. This is implied in the DS version of Sonic Colors after Sonic scores an S rank on Omega's mission. When Omega collects data from Sonic, he says "At this rate, light speed will be exceeded", to which Sonic replies that light speed is slow and not a challenge. However, this may simply be a joke.
 * Sonic has been chased by something numerous times in 3D games: a whale and a boulder in Sonic Adventure, a G.U.N. truck in Sonic Adventure 2, three large spiked wheels and a giant alligator in Sonic Heroes, a fire tornado and another whale in Sonic the Hedgehog (2006), a group of triceratops in Sonic and the Secret Rings, a black hole in the Wii version of Sonic Colors, and a helicopter and a truck in Sonic Generations. The black hole was the only thing that Sonic was not able to outrun.
 * Sonic is notorious for breaking the fourth wall.
 * Apparently, Sonic and his friends are able to breathe in space (as seen in several games and Sonic X), although he cannot breathe underwater without the support of bubbles.
 * All of the cars that Sonic has driven have been sports convertibles, similar to how Amy has only ever driven old-fashioned cars.
 * In 1996, Sonic was the first video game character to be seen in a Rose Parade.
 * The NBA team "The Seattle SuperSonics" is often nicknamed "the Hedgehogs" as a reference to this character.
 * Between 1993 and 1997, Sega sponsored the JEF United Ichihara Chiba football team. During this period, Sonic appeared on the team's uniform.
 * Sonic, along with Knuckles and Dr. Eggman are the only characters who has retained their Japanese voice actor voicing him in all of the Sonic games since Sonic Adventure.
 * Sonic makes a cameo appearance in the Disney film Wreck-It Ralph, in which he is voiced by Roger Craig Smith. Eggman also makes an appearance in the film, thus marking the big screen debut for both characters. Much like Eggman, Sonic's design seems unchanged from his current design in the game series.
 * Whenever Sonic grinds, sparks fly, implying that his shoes (or at least their soles) may be made of metal.
 * In some games, Sonic's quills move as he moves.
 * In modern Sonic games, whenever Sonic spins, a blue aura surrounds him.
 * Sonic was originally supposed to be colored teal, as shown in some of his concept art. He was changed to a darker blue color because the teal kept blending in with the sea in the background of Green Hill Zone.
 * This may also explain why Classic Sonic is teal/light blue in Sonic Generations.
 * In Sonic Rivals 2, this is the only game Sonic's mind has been controlled (by the Ifrit). Among the characters who got mind-controlled by the Ifrit in different storyline scenarios, Sonic says a different line compared to the other characters. (The other characters Tails, Knuckles and Rouge says "Yes, master. I will defeat (partner character's name) while Sonic says "Yes, master. I will take care of (partner character's name albeit in this case it is Tails.))
 * Sonic likes to whistle as heard in several games and Sonic X. However, he whistles more in the Japanese versions of the games and Sonic X.
 * In Sega's other game Jet Grind Radio, one of the characters, Garam, wears a necklace with a skull on it. In an interview with the art director of that game Ryuta Ueda, stated that it's Sonic's skull.
 * Miku Hatsune, a Vocaloid, who's the star of another popular SEGA video game series, has an unlockable Sonic costume to use in gameplay to celebrate Sonic's 20th anniversary.
 * The costume was even designed by Yuji Uekawa, who is the artist of Sonic's current design.
 * She also sang a cover of Live and Learn on a special pre-order album of her game 初音ミク -Project DIVA- Extend to also celebrate his 20th anniversary.
 * Sonic seems to very much care for his shoes, as they are always shown to be shining, possibly for him polishing them, or it could be the material. This is also shown in Sonic Generations, as one of his idle animations is him checking the front and back of his shoes, possibly for dirt.
 * Doctor Eggman may be faster than Sonic in the Chao Garden in Sonic Adventure 2. This maybe a reference to Doctor Eggman always being able to outrun Sonic in games like Sonic the Hedgehog 2 and Sonic & Knuckles.
 * In the Archie Comics series based on Sonic, Bean the Dynamite always refers to him as Mr. Needlemouse, Sonic's original name.
 * Sega have stated that Sonic's personality is based off of the former President of the United States of America, Bill Clinton and his shoes are based on the shoes Michael Jackson uses to moonwalk.
 * Whenever Rouge flirts with other characters, Sonic is one of the two characters who does not fall victim to it, the other being Shadow.
 * At one point in Sonic Unleashed, Eggman called Sonic a "hedge-pig". This may be a reference to the fact that "pig" can be synonymous with "hog", and "hedgepig" means "hedgehog" in Shakesperean language.