Sonic the Hedgehog


 * Sonic the Hedgehog redirects here. For other uses of the term, 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 Adventure 2

Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ) is the title character and main protagonist of the Sonic the Hedgehog series and Sega's mascot. He is a fifteen-year-old, blue, anthropomorphic hedgehog meant to symbolize peace. Like his name and species implies, Sonic can move at the speed of sound (and can even exceed this), with lightning fast reflexes to match it and can as well curl up into a ball, primarily to assail enemies.

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-nemesis Dr. Eggman 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, 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, 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. All that is known is that Sonic was born on Christmas Island and that he has spent his life traveling around the world in search for adventure.

At some point in his life Sonic met Dr. Ivo Robotnik and they became enemies under unknown circumstances. After meeting 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 and foiling the doctor's plans. Despite their many battles, however, Sonic did not really account of his adversary.

Sonic the Hedgehog (1991)
In Sonic the Hedgehog, Sonic heard news about Robotnik invading South Island after the doctor had discovered that powerful relics, called the "Chaos Emeralds", were hidden on the island and 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 were under his 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 securing 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 at Green Hill Zone, where he released the Chaos Emeralds, with their power ensured the island's prosperity.

Sonic the Hedgehog 2
In Sonic the Hedgehog 2, Sonic was traveling the world in the Tornado in search of adventure, when he discovered West Side Island. Landing there and with nothing else to do, Sonic chose to relax and explore this new region. After a few days of exploring, however, Sonic noticed that someone was following him and saw it was a two-tailed fox cub named Miles "Tails" Prower, who had come to idolize him. At first, Sonic chose to ignore the fox and tried to leave. However, as Tails continued to follow him, Sonic came to be impressed by the fox's tenacity and ability to keep up with him, and decided to let him tag along, though he was still not particularly interested in him.

Later, during an early afternnon, Sonic was taking a nap under the Tornado when he was awoken by explosions and saw Badniks attacking West Side Island. Standing besides Tails during the initial attack, Sonic furiously knew that Dr. Robotnik was behind this and ran 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 was turning the island residents into Badniks to find the Chaos Emeralds, which were now located on the island, to create 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. 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. With Tails piloting his airplane, Sonic arrived in the Wing Fortress Zone. As soon as he stepped onboard, however, the Tornado was shot down, forcing Sonci to go on alone. He eventually found Dr. Robotnik, who then escaped in his rocket ship. No sooner, however, Tails arrived in an rocket-enhanced Tornado. Riding with Tails, Sonic and Tails caught up to the doctor's rocket and Sonic grabbed onto it, riding with it to the Death Egg. There, Sonic fought Robotnik's secret weapon, Mecha Sonic, followed by the doctor in the Death Egg Robot. After a heated battle, Robotnik was defeated once again, which triggered a chain reaction that made the Death Egg crash, and Sonic escaped the exploding Death Egg by jumping off into space.

As Sonic descended through the atmosphere, he was saved from his fall by Tails, who caught him on the Tornado, and the two of them flew through the sky together. 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.

SegaSonic the Hedgehog
In SegaSonic the Hedgehog, Sonic was captured by Dr. Robotnik and imprisoned on Eggman Island where he was to be executed along with Mighty the Armadillo and Ray the Flying Squirrel. Teaming up with Mighty and Ray, Sonic escaped his cell to be blown to the other side of the island with Mighty and Ray by a geyser triggered by Robotnik. Working to escape the island, Sonic, Mighty and Ray got to Eggman's Tower where they confronted Robotnik. Robotnik, however triggered the self-destruction of the island, but Sonic, Ray and Mighty escaped just in time.

Sonic the Hedgehog CD
In Sonic the Hedgehog CD, 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 on the other hand, was far from excited to meet her. 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.

Sonic Chaos
In Sonic Chaos, Sonic was out on a causal adventure with Tails when they heard a troubling rumor saying that Dr. Robotnik was seeking the Chaos Emeralds resting on South Island. The two of them returned to South Island only to find the island in a state of total chaos, where they learned that Robotnik had stolen one of the Chaos Emeralds, thereby creating an imbalance that scattered the rest of the Chaos Emeralds across South Island, which was now sinking into the ocean. As such, Sonic and Tails set out to retrieve the Chaos Emeralds before it was too late.

In the ensuring battles, Sonic and Tails managed to recover the lost Chaos Emeralds before Robotnik could, and eventually tracked down the doctor. There, Sonic and Tails defeated Robotnik for good and retrieved as well the Chaos Emerald in his possession, ensuring South Island's safety once more.

Sonic the Hedgehog 3
In Sonic the Hedgehog 3, Sonic was 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 the 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 prepared himself and Tails before heading out with Tails in the Tornado to check out the Chaos Energy 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 and Tails' surprise, they saw it was due to the Death Egg, which they thought had been destroyed, having crash-landed on Angel Island and forced it into the sea. Seeing that the Death Egg was currently being rebuilt, Sonic headed out with Tails to stop Dr. Robotnik from relaunching the Death Egg so he could use it to conquer the world.

As they neared the island, Sonic used the Chaos Emeralds he had collected prior 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 Master Emerald. The echidna, who had been tricked by Dr. Robotnik into believing that Sonic and Tails had come to steal the Master Emerald, somehow forced the Chaos Emeralds out of Sonic, and he returned to his normal form. After the loss of the Emeralds, Sonic could only witness Knuckles snatch and escape with the Emeralds to hide them, leaving Sonic and Tails forced to search the island for them.

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. During their adventure, Sonic and Tails were repeatedly ambushed by Knuckles, but the two of them got through each encounter with their lives, and they recovered the Chaos Emeralds as well. After a long struggle, Sonic and Tails made it to the Launch Base Zone and boarded the Death Egg just as it took off. Here, Sonic and Tails faced Robotnik who had returned to defeat Sonic with excessive force. Nevertheless, Sonic defeated Robotnik again in the ensuring fight, with their resulting battle taking its toll on the Death Egg at a critical point of its launch, making it crash into the Lava Reef Zone.

Sonic & Knuckles
In Sonic & Knuckles, after escaping the Death Egg as it fell down from the sky, Sonic landed safely with Tails' help in the Mushroom Hill Zone. As he saw the Death Egg survive yet another crash landing, this time into the island's volcano, Sonic knew he would not feel at ease unless the Death Egg was completely destroyed. Sonic therefore set out with Tails once more to explore the island to find the Death Egg and destroy it once and for all, and as well discover Robotnik's fate.

As the duo was moving through Mushroom Hill, Sonic was pondering that Robotnik needed time to rebuilt the Death Egg until they spotted Knuckles passing through a hidden doorway in a thicket. After making sure Knuckles was gone, Sonic opened the hidden doorway and looked inside it with Tails where they found a Giant Ring. Enthralled, Sonic touched the Giant Ring, which took him and Tails to the Emerald Shrine in the Hidden Palace Zone where the Master Emerald rested. Here, Sonic and Tails discovered the Chaos Emeralds' connection to the Master Emerald as they were pulled away from him and returned to the surrounding pedestals due to exposure to the Master Emerald. Regardless, Sonic and Tails returned to Mushroom Hill Zone where they began the next phase of their adventure.

Following a long journey across Angel Island, the heroic duo reached the Hidden Palace Zone on their own, where Sonic faced Knuckles in an epic showdown and won. Sonic and Tails then followed the red echidna as he went to check the Master Emerald. When they got to its resting place, however, Robotnik was stealing the Master Emerald for the purpose of powering the Death Egg, 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 Zone, from where the trio witnessed the successful re-launch of the Death Egg. However, Sonic and Tails had to leave Knuckles behind as he was too exhausted from the previous struggles. On their way through the sanctuary, Sonic and Tails encountered the Eggrobo and Mecha Sonic, which they fought several times. On their third encounter, however, Sonic managed to defeat Mecha Sonic. The resulting explosion made a tall pillar nearby crumble, but Sonic and Tails managed to get on the Death Egg just in time by running along the pillar as it was crumbling to pieces.

Onboard the Death Egg, Sonic and Tails encountered Dr. Robotnik for the final showdown. The doctor attacked them with the Kyodai Eggman Robo, powered by the Master Emerald. Sonic and Tails 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 State, chasing the evil genius' across an orbit around the planet. After a long battle, Sonic emerged victorious against the doctor's mechs, descending down to Earth with the Master Emerald. In mid-flight, Sonic was rescued by Tails, piloting the Tornado, as he powered down. The two then brought the Master Emerald back to where it belonged, thus allowing Angel Island to float into the sky once more and make peace with Knuckles before leaving for the time being.

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

Sonic the Hedgehog Triple Trouble
In Sonic the Hedgehog Triple Trouble, Dr. Robotnik had an accident with a weapons test involving the Chaos Emeralds that scattered the Emeralds across the planet. After having gotten wind of Robotnik's incident, Sonic and Tails sprung into action to find the Chaos Emeralds before Robotnik could. While Sonic and Tails ran around collecting information on the Chaos Emeralds, however, Knuckles, who had been tricked by Robotnik into thinking that they sought the Emeralds for the wrong reasons, suddenly popped up and blocked their way. Sonic was then told by Knuckles that he would never get his hands on the Emeralds before taking his leave. As things got more confusing for Sonic and Tails, the dangerous treasure hunter Fang the Sniper also set his eyes on the Emeralds, bent on stealing them for profit. Despite their many adversaries however, Sonic's resolve remained unshaken.

Over the course of their adventure, Sonic and Tails managed to retrieved all but one of the Chaos Emeralds while dealing with and overcoming Fang and Knuckles' respective traps and ambushes along the way. When they arrived at the Dr. Robotnik'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, Sonic and Tails defeated Robotnik and retrieved the final Chaos Emerald from the doctor as he fled. After that, Sonic and Tails found Knuckles imprisoned by the doctor and freed him. Sonic and Tails then made up on good terms with Knuckles once more, before talking off on the Tornado towards new adventures.

Sonic Labyrinth
In 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 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 defeated 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 Sonic the Fighters, Dr. Robotnik had built the Death Egg II from where he planned to conquer the world with his robot armies. Luckily, Tails had built the Lunar Fox that could fly its pilot directly to the new Death Egg to destroy it. However, Sonic learned from Tails that it was a one-seater and it needed all of the Chaos Emeralds to take off. As such, Sonic and Tails entered a fighting tournament where the winner got to collect all the Chaos Emeralds, which was in the possession of all the participants, and as well earn the right to go to the Death Egg II in the Lunar Fox to destroy it.

In order to gather all of the Chaos Emeralds, Sonic had to fight both friends and foes, old and new: Knuckles, Amy, Bark, Espio, Tails, Bean and Fang. At the end of the tournament, Sonic had beaten all the contestants and win their Chaos Emeralds. Before Sonic could be off, however, Robotnik briefly showed up once again in a spaceship and hit him with an unusual ray that created a near-identical copy of himself. The hedgehogs fought, but in the end, Sonicwas 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 turned the tide in the middle of the fight by using the Chaos Emeralds' to transform into Super Sonic once more, defeating his mechanical doppelganger again. He then faced Robotnik himself in a battle suit meant to fight Sonic. At the same time, 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 traveled with Tails and Knuckles to Flicky Island. Having heard legends about the island's Flickies' being the key to find the Chaos Emeralds, the trio journeyed to the island to find these birds, hoping they would lead them to the Emeralds. Once they arrived, however, Sonic and the others found the island in a pandemonium. No sooner, Sonic saw Dr. Robotnik busying himself with turning a Flickies into a Badnik. It turned out that Robotnik was up to his old tricks once more, having 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. Once Sonic mad his presence clear to Robotnik, the doctor told him the futility of his actions before departing in the Egg Mobile.

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

With support from the rescued Flickies, Sonic managed to enter Dr. Robotnik's secret lair, where Sonic confronted Robotnik in a final, lengthy battle. Ultimately, Sonic emerged victorious and escaped 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 Sonic R, Sonic was on a casual adventure with Tails when the two of them came across a large electronic billboard advertising the World Grand Prix, a racing competition to determine the fastest in the world. Despite Tails' urging, Sonic was not interested in participate in World Grand Prix as he knew he was the fastest. However, when he was about to leave, he glimpsed at the list of registered participants and saw Dr. Robotnik's name on it. This made Sonic change his mind, 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 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 Blast
In Sonic Blast, Sonic was napping in his hammock on South Island when he was awoken by a bright light from a Chaos Emerald set nearby which then shattered into five pieces that spread across the island. Robotnik then showed up and revealed to Sonic that he was planning to hit him with a laser beam, but missed and hit the Chaos Emerald instead. Regardless, Robotnik was pleased with the outcome and planned to use the emerald shards to fortify his Silver Castle. After Robotnik left, Sonic was about to head to find the emeralds when Knuckles showed up and joined him in his quest. In the end, Sonic and Knuckles got the emeralds first and foiled Robotnik's plans, and Sonic watched contently from afar as the doctor's fortress crashed.

Sonic Adventure
In Sonic Adventure, Sonic was just returning home after having been gone for a while on a long journey. As he was enjoying himself traveling through Station Square, he saw the Station Square Police fighting Chaos. Sonic then stepped and defeated it, but it managed to escape, leaving Sonic with lots of questions. The following day, Sonic was taking a nap when he awoke to see Tails' crash in his newest plane.

After rushing to Tails' aid, Tails revealed to Sonic that he was working on a new aircraft powered by a Chaos Emerald. Sonic then traveled with Tails to his workshop to see Tails' project, but then Dr. Eggman appeared and demanded the Chaos Emerald for his latest plan. As Sonic refused, he and Tails were attacked by the Egg Hornet. Though they defeated the machine, Eggman snatched the Chaos Emerald and revealed Chaos, who he transformed into Chaos 1 with the Emerald. As Sonic recognized Chaos, 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 Eggman escaped, Sonic was determined to stop him and set out with Tails to get the Chaos Emeralds before Dr. Eggman could give them to Chaos.

Eventually, Sonic and Tails retrieved the first two Emeralds in Windy Valley and Casinopolis respectively. After leaving Casinopolis, however, Dr. Eggman appeared and disabled them with a sleeping gas, before stealing one of their Chaos Emeralds. Unshaken, Sonic and Tails continued their search. After finding a Chaos Emerald in Ice Cap, however, Sonic and Tails were attacked by Knuckles, who had been tricked by Eggman into believing Sonic had stolen parts of the Master Emerald. With no interest in reasoning with Knuckles when he vaguely demanded their Emeralds, Sonic fought him until he dropped the two Chaos Emeralds, which were then taken by Dr. Eggman who had just arrived. Eggman then gave the Emeralds to Chaos 2, transforming it into Chaos 4, but Sonic and the others defeated it. As Eggman escaped to his Egg Carrier, Sonic and Tails followed him in the Tornado. In the ensuring aerial fight with the Egg Carrier, however, the Tornado was shot down.

After being shot down, Sonic landed near Station Square where he began to look for Tails. He soon ran into Amy, who asked him to help her protect "Birdie", a Flickey she had met. While Sonic had no interest in that request, Amy followed him regardless. Soon after, they were attacked by ZERO, which made Amy escape into Twinkle Park, forcing Sonic to follow her, but lost track of her. He eventually saw Amy being kidnapped by ZERO and headed to the Mystic Ruins to cut ZERO off there.

At Mystic Ruins, Sonic cornered ZERO, only for it to escape with Amy to the Egg Carrier. Sonic then pursued the Egg Carrier through Red Mountain until he reached a dead end, but then met Tails in the Tornado 2. The duo then gave chase on the Tornado 2 and landed on the Egg Carrier. As they headed for the bridge to find Amy, Sonic and Tails eventually found her and saw Eggman take a Chaos Emerald from Birdie, before being attacked by E-102 Gamma. Before Sonic could destroy Gamma though, he was stopped by Amy, who said it was her friend, and Sonic complied. As the Egg Carrier began to lose altitude, Sonic had Tails escort Amy to safety while he chased after Eggman.

Eventually, Sonic found Eggman, but also saw that Chaos had become Chaos 6. Big the Cat then arrived and said that his friend Froggy was trapped inside Chaos, and Sonic promised to help save him. After saving Froggy, Sonic defeated Chaos 6, only for Knuckles to appear as Eggman escaped. Sonic then chased after Eggman off the Egg Carrier and into the Mystic Ruins, where he found an ancient temple and a mysterious light that led him into the temple. There, Sonic found a mural depicting a monster, and was taken back in time to see the Altar of the Emeralds lying in ruins and Tikal trying to stop a catastrophe occurring. After returning to the present, Sonic spotted Eggman and followed him to 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.

As he rested from his ordeals, Sonic heard from Tails that Angel Island had fallen. As they arrived there to investigate, Sonic and Tails found both Knuckles and Eggman knocked out and learned from them that Chaos was still alive, had rebelled against Eggman, and now had six Chaos Emeralds. As Eggman left to get revenge, Sonic and Tails were about to head out to get the last Chaos Emerald in the Tornado 2 before Chaos, when Sonic was drawn into the past again. There, he saw the Knuckles Clan's attack on the Altar of the Emeralds, the event that drove Chaos to destroy the world to begin with and Tikal sealing herself and Chaos inside the Master Emerald.

Returning to the present, Sonic and Tails went to find the last Chaos Emerald, but Chaos beat them to it before their eyes. Sonic then returned to Station Square which was attacked by Perfect Chaos. After he saw 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 behavior. When Perfect Chaos released the partially drained Chaos Emeralds, Tikal wanted to seal Chaos again, but Sonic claimed it would not work as Chaos would still be full of rage 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. Sonic then transformed into Super Sonic and defeated Perfect Chaos, while returning it to a benevolent creature again. Sonic then saw with his friends Chaos and Tikal depart to live in peace, before he noticed Eggman making his escape. Sonic then 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. Arriving in the Temple of Light, Sonic and his friends met Lumina Flowlight, the one responsible for bringing them to Maginaryworld. Lumina introduced Maginaryworld to the group and explained that she had brought them here to help her restore the Perfect Precioustone which had been shattered by Void. Its pieces had then been scattered, and their guardian and protector of the Perfect Precioustone, Illumina, had vanish as a result. If the pieces were not recovered in time, Void's darkness would corrupt Maginaryworld until it was destroyed. With everyone in agreement, Sonic promised to help Lumina. Beginning their adventure with Lumina, Sonic and the group first traveled to Emerald Coast, which was becoming a frozen wasteland. There, they found both the first Precioustone and brought the world back to normal. Sonic and the group then ventured to Fire Bird where they found the next Precioustone and freed the true form of the world, a phoenix, from imprisonment. After that, they got to the Nature Zone which was losing life thanks to Void's darkness. Sonic and his friends, however, found the next Precioustone and as well restored the jungle's natural state. From there, they traveled to Riot Train where they recovered the fourth Precioustone and Sonic, Tails, Knuckles and Amy brought the rampaging train there to a halt. Riding on the train, Sonic and his friends made it to the Fourth Dimension Space where they recovered the final Precioustone. Along the adventure, Sonic and the others had a vision whenever they got a Precioustone where they met Void. In these visions, Sonic and the gang initially stood defiant against Void, but they soon saw that Void was lonely and depressed which touched their hearts, and they eventually realized that Void and Lumina embodied the positive and negative aspects of dreams and were two halves of the same being.

After all the Precioustones were returned to the Temple of Light, Sonic and the group headed there when Void went to the Temple to seek out the Perfect Precioustone again. As Sonic, Lumina and the rest got to 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 Perfect Precioustone was not recovering. As they tried to cheers up Lumina, Sonic found Void in the form of a dark gem. Sonic then explained to Lumina that she should not reject Void as the negative feelings that he embodies makes it possible for people to have dreams and make them stronger.

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 Perfect Precioustone, and Lumina and Void returning to their original form, Illumina. As Marginaryworld 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 was on his own when he suddenly met the Guardian Units of Nations who arrested him, claiming he had robbed a federal reserve bank of a Chaos Emerald. In truth, Sonic was mistaken for Shadow the Hedgehog, who had been released by Dr. Eggman to assist him in his plans for world domination and was the true culprit behind the theft. Handcuffed, Sonic was brought onborad a military helicopter to be transported, but while over Central City, Sonic broke free and escaped into the city.

After escaping G.U.N. and destroying a Bigfoot vehicle, Sonic encountered Shadow. Realizing that Shadow was the one behind the false accusations, Sonic demanded answers and attacked. Instead, Shadow used Chaos Control with the stolen Chaos Emerald to avoid Sonic's charge, before disappearing in a flash. No sooner, Sonic was surrounded by G.U.N. soldiers and robots and was arrested once more.

Following his arrest, Sonic was locked up on Prison Island. The following day though, Sonic found Amy at his cell, who revealed that she and Tails had come to break him out. As Sonic said that it was Shadow's fault that he was here, Amy revealed Shadow was on the island. Sonic tried to ask Amy about Shadow, but changed his mind when Amy said she would reveal more if he married her. Regardless, Sonic was freed from his cell and learned from Amy that Eggman was behind it all, before leaving to find Shadow. When he found Shadow, Sonic fought him until he heard that the island was about to explode. Sonic, however, managed to find Tails and Amy and escape 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 made Sonic realize that this was the reason why Eggman was collecting the Chaos Emeralds. As the police arrived, Sonic distracted them to give Tails time to work on how to track Eggman. He eventually contacted by Tails and heard that they could use the communication link to Eggman in the President's limousine to find Eggman. Meeting up inside the President's limo, Sonic and Tails learned Eggman was on the Space Colony ARK, where Sonic assured the President they will handle the problem.

With Knuckles' help, Sonic, Tails and Amy were led to Eggman's base where they hoped to find a space ship that could take them to the ARK, to which Sonic planned to get to the Space Colony ARK from there and destroy the Eclipse Cannon. After infiltrating the base, Sonic enlisted Knuckles to find the keys center of the base. When they reached the center, however, the group was ambushed by Eggman and his Egg Golem. Sonic, however, 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 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 got a fake Chaos Emerald from Tails that he could use to destroy the Eclipse 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, who demanded that Sonic handed over the final Chaos Emerald or he would kill Amy.

When Sonic arrived in the ARK's central control room, he thought he could trick Eggman into taking the fake Emerald. Eggman, however, saw through this and Sonic was captured in a capsule set to explode, before being ejected into space. Before the capsule could explode, however, Sonic used Chaos Control with the fake Emerald to warped himself back to the ARK. There, Sonic met Knuckles and had 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 and fought him once more. After Sonic won, he managed to destroy the Eclipse Cannon just before it fired.

When Sonic and Knuckles returned to the main control room, they 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.

When Sonic and Knuckles made it to the core they were then intercepted by the Biolizard, but Shadow then appeared and held it off, while they deactivated the Chaos Emeralds. In response, the Biolizard warped outside the ARK and merged with it, becoming the Finalhazard and kept the ARK on its collision course. Determined to stop it, 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 Chaos Control.

As he came back on board, Sonic informed the others that Shadow had seemingly died from the effort, before giving Shadow's Inhibitor Ring to Rouge and assuring her that Shadow was a great hero that he would never forget. After processing Shadow's death, Sonic suggested that they all went back home as Sonic bid farewell to his worthy rival.

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 occasions. 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, Sonic learned that Dr. Eggman kidnapped Tails and Knuckles as he tried again to build the Eggman Empire and 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 regardless. 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's (with Vanilla inside) fall, but the re-entry 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 travelled 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. Sonic then chased after Eggman and Gemerl, until Gemerl betrayed Eggman, took the seven Chaos Emeralds from Sonic and transformed into Ultimate Gemerl. Seeing what had to be 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 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 on his own world tour when he met Tails and Knuckles in the Tornado 2, who gave him a letter from Dr. Eggman. In the letter, Eggman claimed to have created "the ultimate weapon" to conquer the world and that he challenged them to stop him within three days. Confident as ever, Sonic took off to stop Eggman with Tails and Knuckles right behind him, officially forming Team Sonic.

Team Sonic began their mission by tracking down Dr. Eggman and found him in the at Ocean Palace. There, they defeated his Egg Hawk, but Eggman escaped. After that, Team Sonic tracked Eggman to Grand Metropolis. After liberating the city from Eggman's control, and escaping the Power Plant, Team Sonic came across Team Rose. After being forced to fight Team Rose, Sonic used the fight as a distraction to escape Amy.

As they arrived in Casino Park, Sonic proposed they took some time off, but was pressed on by Tails. After passing through the city, Team Sonic was attacked by Eggman's Robot Carnival, which they defeated. As they chased Eggman to Rail Canyon and only having until sunset, Sonic ordered his team to go full speed ahead to the terminal station. When they reached Bullet Station and destroyed Eggman's base there, the team found Eggman in the Egg Albatross. After destroying the Egg Albatross, however, Team Sonic discovered that the Eggman they had been chasing was a fake and that their challenge letter was to distract them while Eggman launched his Egg Fleet. Enraged, Sonic ran off in pursuit of Eggman.

Resuming their chase after Eggman through the jungle, Team Sonic encountered Team Dark. Amazed to see Shadow was still alive, Sonic and his team fought Team Dark in a skirmish to decide who went after Eggman. After the battle, Sonic saw Eggman and Shadow head towards Hang Castle and lead his team down the same way. After infiltrating the castle and escaping Mystic Mansion, Team Sonic was attacked by Eggman's Robot Storm, but they quickly dispatched them.

After that, Team Sonic got to the Egg Fleet, where they traveled across the flagships to the Final Fortress, where they destroyed the flagship's core. Afterwards, Team Sonic found Dr. Eggman in his Egg Emperor and defeated him. After heavily destroying the Egg Fleet, Sonic was teased by Knuckles on how he would not have done this on his own, but surprised Knuckles by agreeing with him and thanked both him and Tails for their help. No sooner though, Amy came running and Sonic tried to escape from her.

Some time later, Team Sonic and the others witnessed the return of Metal Sonic, who had been staging the team's adventures and impersonating Eggman so he could follow them and copy their data in a plan to conquer the world himself, as he transformed into Metal Madness. 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 was joined by Knuckles and Tails while the other teams volunteered to buy them some time. Accepting everyone's help, Sonic and his team got the Chaos Emeralds ready while Team Rose, Dark and Chaotix fought Metal Madness.

As Metal Madness transformed into Metal Overlord, Sonic transformed into Super Sonic, whilst granting Tails and Knuckles a Super Shield each. The team then took off and defeated Metal Overlord. Back on the flagship, Sonic stood triumphant over Metal Sonic, until he saw Amy approached him. Sonic then told Metal Sonic 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 find 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 tried to chat friendly with Shadow after completing their objective. Though Shadow rebuked his friendly attitude. Sonic expected that much and suggested a friendly face-off, but was declined. After Doom's Eye arrived and told them where the next Chaos Emerald was, Sonic 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 destroyed 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. nevertheless, 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 and informed him of the Black Arms' activities before inviting 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 and informed him of the Black Arms' activities before inviting 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, the Black Arms' forces were waiting for them. Excited about the challenge, Sonic invited Shadow to join him, before hurrying outside to engaged the enemies with Shadow.

Space Gadget
When Sonic and Shadow made it on board the Space Colony ARK as they followed the Black Arms, 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 on board the ARK.

In the Hero scenario, where Shadow accept the challenge, Sonic was beaten in the race and Shadow claimed the Chaos Emerald. As the two make their way through the ARK's interior, Sonic caught a glimpse of the Black Comet. When Shadow asked what it was, Sonic soon 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 there.

Lost Impact
In the Hero scenario of Lost Impact, Sonic made it on board the Space Colony ARK with Shadow as they chased the Black Arms to the ARK. As the two make their way through the ARK's interior, Sonic caught a glimpse of the Black Comet. When Shadow asked what it was, Sonic soon 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 there.

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

Hero Scenario
In the Hero 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 confronted him 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 him why he sided with the Black Arms. As Shadow revealed that his only interest was to beat Sonic, Sonic was amused by this challenge. 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 an 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 him. 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 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 him. 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 what 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 found a Gizoid robot during a scroll on Emerald Beach. As he examined it, the Gizoid told him to show his power, and Sonic displayed some fighting moves, forming a Link with it. Sonic decided to take it to Tails to get it examined, but ran into Shadow, who demanded the Gizoid. Sonic refused though, and defeated him battle. Afterward, Shadow told Sonic to keep the Gizoid from Eggman and left. Though confused, Sonic presented Tails with the Gizoid, but then saw Rouge on the beach and left to investigate. Meeting up with Rouge, Sonic heard she and the government were after the Gizoid too, but Sonic got her to leave after he defeated her. When returning to Tails' Lab, Sonic encountered and defeated an E-121 Phi before finding Tails unharmed. Tails then revealed to Sonic that the Gizoid evolved with each Chaos Emerald inserted into it and that it could copy fighting moves. Thrilled, Sonic decided to train it.

After some training, Sonic named the Gizoid "Emerl", and they and Tails decided to see if Knuckles had a Chaos Emerald to help Emerl evolve. On the way, they faced an E-121 Phi and Chaos Gamma, but defeated both. When they arrived at Knuckles’, however, Knuckles mistook Emerl for an E-121 Phi and attacked him. After Emerl defeated Knuckles, Sonic got Knuckles' Chaos Emerald and they inserted it into Emerl.

Sonic continued training Emerl for a while, until Tails decided to take Emerl to Central City to examine him. When they returned, Sonic learned from Tails and Rouge that Emerl was a weapon of mass destruction. However, Sonic refused to believe it and suggested they could reprogram him, and Rouge revealed that they could reset Emerl by inserting all seven Chaos Emeralds into him and giving him an unknown keyword. While Sonic questioned Rouge's motives, he nevertheless introduced her to Emerl by forming a Link with her, but then Rouge suddenly left. Knuckles then arrived and Sonic told what had happen before he and Emerl began to tease him, which eventually let to a fight between the three of them.

Sonic continued Emerl's training from there, until he saw Amy coming and ran away. When he returned, Sonic learned that Rouge had stolen Emerl. Howver, Sonic soon after found Emerl with Rouge and engaged her in battle with Tails and Knuckles' aid, and eventually made Rouge surrendered Emerl as she thought he was too much trouble.

Later on, Sonic left Emerl with Tails for a while. When he returned, he learned from Emerl that he had been training with Knuckles and that Knuckles had been tricked by Eggman during his absence.

Soon after, Sonic and Emerl met Amy again, who viewed Emerl as hers and Sonic’s "baby". As Sonic was berated by Amy for how he had raised Emerl, Sonic ran off when Emerl made a bad choice of words. He later returned to them, and was told by Amy that he had to marry her now since she had helped raising Emerl, but Sonic escaped after tricking Amy to close her eyes.

Sonic and Tails later left Emerl in Amy's and Cream’s care, when they checked out a lead on a Chaos Emerald, which turned out to be fake. Later, Sonic was contacted by Eggman who claimed he held Cream and Emerl hostage, but he did not believe him when he could not prove it (as Emerl and Cream had escaped). He later saw Eggman captured in his own "spiky rodent trap" by Emerl and Cream on-screen, and headed out to pick them up.

Sonic later met Shadow again and thought he want to capture Emerl, but heard that it was not his intention. Shadow then told Sonic that Emerl only needed one more Chaos Emerald to awake his full power, which would destroy the world, but Sonic believed Emerl would not do that since he had a heart like Shadow, who was also a top secret ultimate weapon. As Shadow brushed off his arguments, Sonic gave up trying to convince Shadow and let him have Emerl. Despite Emerl being attracted to Shadow's Chaos Emerald, Sonic let Emerl go with Shadow, believing he would learn who he really was with his help. When Emerl then came to fight Shadow after having reset to a good robot, Sonic teamed up with Shadow to test Emerl's abilities to the fullest. After the fight, Sonic saw that Emerl no longer needed him and told him to live his life on his own, though he noted his punches could use some work.

Later on, Sonic and Emerl met Eggman, who announced that he would use his Final Egg Blaster on his newest Death Egg to conquer the world before escaping. Sonic and Emerl then met up with Tails, who had brought a transporter to the Death Egg with him. Tails, however, 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, Sonic and his friends watched Emerl through a monitor on the Death Egg and cheered him on. After seeing Emerl defeat Eggman, Sonic saw Eggman firing the Final Egg Blaster, destroying some stars. This display of power caused Emerl to revert to his original programming and Eggman tried to assume control over Emerl, but he knocked the doctor away and prepared to fire the Final Egg Blaster on the Earth. As Sonic tried to tell 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' energies inside Emerl. With the transporter back online, Sonic arrived on the Death Egg, but Emerl smashed the Master Emerald. Tails then told Sonic that he could reverse Emerl's programming by damaging him, but it would destroy Emerl in the process. Seeing no other choice, Sonic, with a heavy heart, engaged Emerl in battle. Seeing the overwhelming strength of Ultimate Emerl, Sonic fought at full strength and defeated him.

As Emerl began to break down and say farewell, Sonic, in a rare chase of emotional distress and denial, tried to assure Emerl that everything would be fine, but to no avail, and Emerl disappeared before his eyes. Sonic then returned to the Earth and found Cream crying over Emerl’s death, but Sonic told her that Emerl was still with them in the Emerald Shards. As Tails then wondered if they would ever see Emerl again, Sonic was positive they would.

Sonic Rush
In Sonic Rush, Sonic came across Dr. Eggman, who claimed that he would soon possess "the ultimate power". After defeating Eggman, Sonic saw that he dropped a Sol Emerald, but then suddenly he met Blaze the Cat, who took the emerald and left. Sonic later met up with Tails and explained about what he had just witnessed. Pumped up by this new challenge, Sonic headed out with Tails to stop Eggman.

At Water Palace, Sonic first encountered Dr. Eggman Nega, a new foe that had teamed up with Dr. Eggman. After defeating him, Sonic and Tails headed to Tails’ workshop, where they learned that there was a rift in the space-time continuum that threatened reality itself. While Tails suspected Eggman Nega may be involved in this, Sonic thought that Blaze might also be a part of this. While searching for info and fighting Nega, Sonic learned from Vanilla that Cream was with Blaze. After thanking Vanilla for where to find them, Sonic ran off to find Blaze and get some answers.

During their search, Sonic and Tails came to a path closed by rocks from where Knuckles emerged. Sonic and Tails then heard from Knuckles that he got trapped under the rocks when casing Blaze. Ignoring Knuckles as he smashed rocks in fury, Sonic and Tails continued through the path he had cleared. After that, they found Blaze and Cream, and Sonic asked Blaze if she knew anything about Eggman Nega. Blaze told him that she would deal with this crisis and Eggman Nega alone, but Sonic told Blaze that things did not work that way around here. Blaze, however, firmly insisted and left with Cream, but Sonic and Tails followed them.

While tracking Blaze, Sonic ran into Amy. Sonic tried to ask Amy if she had seen Blaze, but when Amy took it as a sign of affection for Blaze, and Sonic asked Tails help. Amy eventually cooled down and providing directions for where Blaze went, to which Sonic immediately took off.

Eventually, Sonic tracked Blaze to Dead Line where they faced both Eggmans. While Sonic insisted on helping, Blaze refused his help and tried to force him to leave by fighting him. Sonic tried to make Blaze stop and told her not to carry everything on her own, but to not avail. As their fight ended in a draw, Sonic saw that Blaze was still willing to protect the Sol Emeralds even when completely worn down. Understanding Blaze's rough past, Sonic told her not to handle too much on her own and be true to herself, making Blaze realize she could rely on others, and the two of them 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 Eggman and Eggman Nega were to blame, Sonic decided to confront Eggman Nega on Blaze's behalf, since she was not in shape to fight. Just before Sonic could leave, however, they noticed Cream was gone and found a letter left by Dr. Eggman that said he held Cream hostage and that Blaze had to come to Point W alone. Sonic suggested that they got everyone together to help since this was likely a trap, but Blaze insisted on going alone because Cream was her friend, which Sonic allowed. While Tails doubted this, Sonic assured him by saying that believing in someone was a part of friendship. Sonic himself then faced and defeated Eggman Nega. After 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 when Eggman and Eggman Nega attacked her in the Egg Salamander and drained the Sol Emeralds' power. As Sonic arrived, the doctors to prepare for their coming fight, and found Blaze in despair. Sonic, however, 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 made, the Sol Emeralds would never lose their power, causing the Sol Emeralds to recharge. 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, but Sonic promised that they would meet again. The two of them then shaked hands as the space-time continuum pulled them apart and returned them to their own worlds. When Sonic then returned home, he found Cream, who was sad over Blaze’s departure, but cheered her up by telling her that Blaze would be back.

Sonic Rush Adventure
In Sonic Rush Adventure, Sonic and Tails were out in the Tornado investigating an unknown energy reaction, but they got sucked into a hurricane. Sonic and Tails then washed ashore on Southern Island where they met Marine the Raccoon. Finding themselves in unknown territories, Sonic and Tails decided to explore the surrounding islands. The next day, Sonic and Tails found Marine accidently destroying her own vessel that she was building. The duo then helped Marine constructing a new waterbike and the trio began exploring the surrounding islands.

On their journey, the group was attacked by several robotic enemies. Sonic also encountered Johnny, who became his rival in waterbike racing. When arriving at Coral Cave, Sonic met Captain Whisker and his 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. Sonic then teamed up with Blaze to fight off the Ghost Kraken.

After the fight, the pirates escaped with the Jeweled Scepter, which was hidden in Coral Cave and which Blaze tried to protect. As Sonic asked Blaze why she was here and not in her own world, they realized they had been transported to Blaze’s world during the storm. After explaining their story to Blaze, Sonic then suggested to Blaze that they should work together to get the scepter back which posed a threat to their worlds 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 find the pirates’ hideout in some ancient ruins. Before heading in there, however, Sonic, Tails and Blaze decided to make Marine stay behind as she could endanger the mission. While Sonic and Tails tried to be gentle about it, they silently agreed with Blaze when she told Marine she was a nuisance, making Marine run off crying and yelling.

At the pirates’ hideout, Sonic faced Whisker and Johnny, alongside Blaze. Despite beating them, however, Whisker escaped and Sonic saw Marine arrving and going after the pirates, 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 their ship. Seeing Marine had 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 learned that the Jeweled Scepter had been stolen again. In the wake of an earthquake, the thieves revealed themselves to be Dr. Eggman and Eggman Nega in the Egg Wizard, who were behind the pirates, so they could use the Jeweled Scepter's incredible power to build Eggmanland upon both worlds. As Sonic and the gang pursued the Eggmans, the villains tapped into the Power of the Stars with the scepter. Sonic and Blaze used the Emeralds to become Super Sonic and Burning Blaze. As they were about to defeat the Egg Wizard, however, Eggman Nega tried to destroy them and the world, but Marine distracted them, allowing Sonic and Blaze to destroy the Egg Wizard.

The next morning, Tails constructed a vessel for him and Sonic to return home in. Just before leaving, Blaze suggested to Sonic that the Sol Emeralds and the Chaos Emeralds were responsible for meeting each other again, which Sonic remarked that they could never know for sure and then shaked hands with Balze once more, signifying their growing friendship and respect. Just as they were about to take off, however, Sonic and Tails saw Marine traveling in her new vessel to say goodbye. After promising Marine that they would meet again, Sonic and Tails headed back to their own world.

Sonic Riders
In Sonic Riders, Team Heroes arrived in Future City to search for a Chaos Emerald, when they saw the Babylon Rogues. Tails read on his radar that they had the Emerald, and Sonic ran off to intercept them. After Knuckles knocked Sonic off his Type-S, Sonic chased after Jet on the Type-S, but was blown off the Extreme Gear by Jet, and the Babylon Rogues escaped.

The next day, Team Heroes 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 to claim all seven. Sonic was initially suspicious, but when he saw that the participants Dr. Eggman had found were the Babylon Rogues, he decided to enter the competition.

After the qualifications rounds, Sonic was with his team when he met Amy, who had also signed up for the tournament, much to his discomfort. After hearing Tails explanation about the legends of the Babylon Rogues and Babylon Garden, the group met Wave the Swallow who mocked Tails' Blue Star (and placed a bomb on it), leaving Sonic annoyed by her behavior. No sooner though, Sonic and the other hurried to next race.

As Sonic made it to the semifinals, he took time off to practice his Extreme Gear skill with his team when they were interrupted by Jet, who mocked Sonic before leaving. While angered, Sonic did not believe he should underestimate Jet. Tails then began to doubt the Blue Star he had made for Sonic, but Sonic told him not to worry.

As Sonic and his team made it to the finals, Sonic received some final taunts from Jet before the race, but he vowed not to lose. At the end of the race, Sonic was about to win, but Wave detonated the bomb under Sonic’s Blue Star, causing Sonic to lose to Jet. To add pain to insult, Sonic was mocked by Jet for his loss, making him furious.

Afterward, Sonic and the others saw Jet claim and used 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 went after Eggman with the Blue Star II, but was locked in a race with Jet, who was after Eggman too.

Sonic eventually beat Jet and cornered Dr. Eggman, but stopped when Eggman revealed he held Amy hostage. Sonic, however, dived into Eggman (and Amy) and blew them away. Sonic then took back the Key to Babylon Garden and handed it back to the Rouges despite Jet's refusal. As the Rogues went to claim the treasure, Sonic decided to leave, but Amy was furious at him for endangering her and chased after Sonic with her Piko Piko Hammer. No sooner, Sonic and the others heard a roar from inside Babylon Garden and decided to check it out. There, 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. With the whole ordeal over and with their rivalry more friendly, Sonic promised Jet when he was about leave with his team that he would be ready to race him the next time they met.

Sonic Riders: Zero Gravity
In Sonic Riders: Zero Gravity, a few months after the World Grand Prix, Sonic was driving with Tails and Knuckles through Monopole, fumbling thoughtfully with a mysterious meteorite Tails had found the other night. On their way to Megalo Station, they 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, but Sonic was saved by the meteorite, which could manipulate gravity, as it activated.

Rejoining his friends, Sonic tried to hide from the robots when Amy suddenly snuck up on him and revealed she was being chased by the robots because she had a meteorite similar to Sonic’s. Sonic then decided to head to robots' creator, MeteorTech, to get some answers. There, 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. Initially eager to face Jet’s challenge, Sonic decided to postpone it when more robots showed up.

As Sonic raced Jet to the control room, Sonic and the others were surprised to find Dr. Eggman, who was the owner of MeteorTech, and Sonic suspected he was behind the robot rampage. While Eggman claimed to have no part in it, Sonic got suspicious when Eggman recognized his Ark of the Cosmos. After forcing him, Eggman revealed that MeteoTech’s mother computer was powered by one of the Arks of the Cosmos and that the robot's 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 left with his friends to save her.

When they found Amy, Sonic, Knuckles and Tails heard from Amy that SCR-HD had suddenly blown up and that Storm had taken its Ark of the Cosmos. However, Tails deduced that they had to remove the Ark of the Cosmos in MeteoTech’s mother computer to stop the robots. As the group tried to figure out where the mother computer could be, Amy remembered Storm mentioning Gigan Rocks, which held information about the Ark of the Cosmos. Sonic and the others therefore went there to find clues.

At Gigan Rocks, the group learned from the ruins that the Arks of the Cosmos were power units for an ancient spaceship, which 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 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. As Tails conclude that Eggman planned to use them to control all the world's robots as a plan for world domination, Sonic was about to head out, but Jet intercepted him and demanded a race to the Arks of the Cosmos, which Sonic agreed to.

The race eventually came to a draw, as both Sonic and Jet stopped Eggman at the same time and stopped the robot rampage. After Babylon Garden appeared due to all Arks of the Cosmos being present, Sonic gave his Arks of the Cosmos to Jet and took his leave, content with settling the score with Jet at the next World Grand Prix. However, SCR-HD then appeared and took all five Arks of the Cosmos to Babylon Garden, which transformed it into Astral Babylon and made it form a black hole that threatened to consume the planet. Sonic then headed to Astral Babylon with his team and the Babylon Rogues to disconnect the ship's engine and stop the black hole where they faced and defeated Master Core: ABIS, thus saving the world.

Later, Sonic, Knuckles, Tails and Amy later returned to Monopole, where they learned from Tails of how the Arks of the Cosmos made the robots to go amok. No sooner, Sonic was challenged by Jet to a new race, which Sonic accepted, 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 rewards. 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. Sonic and Jet them faced each other in a on-on-one race, where Sonic emerged victorious. After the race, Sonic commented that 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 number 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 gather 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. 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)
In Sonic the Hedgehog (2006), Sonic visited Soleanna during a festival where he saved their monarch, Princess Elise, from Dr. Eggman, who was after the Flames of Disaster, known as Iblis, to help him rule the world, which was sealed inside Elise. As Sonic brought Elise to safety, he was distracted by Eggman's mechs while Eggman kidnapped Elise and escaped, though not before Sonic received her Chaos Emerald. Determined to save Eilse, Sonic teamed up with Tails the next day and tried to catch the Egg Carrier at Wave Ocean, but failed.

After returning to the city, Sonic and Tails learned Eggman was in Dusty Desert. There, they found Elise only for Eggman to attack them with the Egg Cerberus. After Sonic destroyed it, Sonic escaped Eggman's forces with Elise by letting Tails create a diversion. As they escaped, Elise treated Sonic's injuries and apologized for them, but Sonic insisted her smile was all he needed. Sonic was then filled in on the Flames of Disaster and Solaris (Soleanna's sun god) by Elise, who grew worried of what Eggman would do with it, Sonic cheered her up with a run and gave her some advice to go by.

Back in Castle Town with Elise, Sonic was attacked by Silver the Hedgehog, who claimed that Sonic would destroy his world. Sonic initially had the upper hand, but Silver catch him off-guard and incapacitated him. Meanwhile, Sonic saw Eggman kidnap Elise again, but was unable to save her. Luckily, Sonic was saved when Amy stopped Silver, and he cased after Eggman. Sonic then met up with Tails and Knuckles, who gave him a message from Eggman demanding Sonic’s Chaos Emerald in exchange for Elise. Despite knowing it was a trap, Sonic, Tails and Knuckles arrived at White Acropolis, where Sonic gave Eggman the Chaos Emerald, but was tricked and sent to the future by Eggman's machine with his friends. Arriving in a ravaged future, they met Shadow and Rouge. They then decided to work together to get home by finding enough Chaos Emeralds for a Chaos Control powerful enough for time travel.

While searching for the Chaos Emeralds, Sonic, Tails and Knuckles briefly saw Silver and Blaze talking with Mephiles before they went back in time. From their database, the group learned that Elise would die in the Egg Carrier's future crash-landing, leaving Sonic more determined than ever to save her. Locating a Chaos Emerald in Flame Core, Sonic his friends met up with Rouge and Shadow and journeyed there, where they attacked by Iblis when the found the Emerald. After Sonic and Shadow defeated it, they used their Chaos Emeralds to make a rift back to the present. Though it, Sonic, Tails and Knuckles got back to the present, though Shadow and Rouge did not follow them.

Locating Elise on Eggman's train, Sonic managed to save the princess, but was attack by Silver again. While caught in the fight, Sonic saw Eggman kidnap Elise again. Fortunately, Shadow arrived and held Silver off while Sonic save Elise again and destroyed the Egg Genesis. As they fled from Eggman's robots, Sonic took Elise to a beautiful location to cheer her up. There, Sonic told Elise that he would leave once he defeated Eggman, but cheered her up when she was sad about his departure.

After that, Sonic returned Elise to the castle, but after hearing that Eggman kidnapped Elise again, he ran off to save her. On his way, Sonic was attacked by Eggman's robots, but was assisted by Silver who now wanted help Sonic. Unfortunately, Sonic was too late as Eggman’s ship crash and exploded with Elise inside as predicted. However, Silver had the plan to send Sonic back in time to save Elise. Using Chaos Control and two Chaos Emeralds to created a rift, Sonic promised Silver to change his future by saving Elise before heading into the rift. Arrive at the day before, Sonic bordered the Egg Carrier and defeated Eggman in the Egg Wyvern before narrowly escaping the exploding Egg Carrier with Elise.

On their way back to the city, Sonic and Elise were distracted by a Chaos Emerald. Mephiles then appeared and impaled Sonic, killing him. As Elsie cried over Sonic's death, Iblis was released from within her and Mephiles merged with Iblis, remaking Solaris and create a spatial distortion that transported Sonic's body and Elise to the End of the World. There, Sonic's allies and Eggman saw Sonic’s dead body in Elise’s arms, each showing sadness at his death. As they learned about Solaris’ intention to consume time, Silver planed to destroy Solaris, but Shadow noted they stood no chance without Sonic.

Sonic’s soul had yet to pass on at this point though, and Elise sensed his presence. Realizing that it was not too late, everyone gathered all the Chaos Emeralds to restore Sonic to life. Revived as Super Sonic, Sonic turned Shadow and Silver into Super Shadow and Super Silver and they defeated Solaris. Sonic and Elise were then sent back to when Solaris was just a flame. If Elise blew out the candle it would destroy Solaris forever, but it would mean the events leading to Elise's meeting with Sonic would never had happened. Sonic, however, encouraged Elise to accept things as they were and she extinguished the candle. Time was reverted, but Sonic still traveled to Soleanna where he created a wind as he passed Elise. As the festival proceeded, Sonic watched on happily, hinting that he still remembered this adventure.

Sonic Rivals
In Sonic Rivals, when Onyx Island appeared at sea, Sonic and Tails investigated it, suspecting it was another of Dr. Eggman's schemes. When 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). Sonic confronted the doctor, but Eggman Nega pulled out a card depicting Amy Rose, leaving Sonic shocked. Eggman Nega explained he had turned Amy into a card with a special camera, but Sonic did not believe it. However, as Tails stating his opinion about Eggman Nega's claim, a flash from Eggman Nega's camera blinded Sonic, and when he regained his sight, Tails was gone. Sonic asked Eggman Nega what he had done, and the doctor revealed that he had turned Tails into a card as well. At the same time, Knuckles appeared, believing Eggman Nega had stolen the Master Emerald. As Eggman Nega showed he had turned the Master Emerald it into a card as well, he escaped, and Sonic raced Knuckles to see who got to face Eggman Nega first.

Eventually, the two found Eggman Nega and teamed up to fend off the Egg Turtle, but Eggman Nega escaped. As Sonic followed him, however, he ran into Silver, 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 they raced after Eggman Nega. As Sonic reached Eggman Nega, he demanded the cards back, but Silver insisted on going first, 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, until Silver teleported Sonic to another location. Surprised, Sonic looked around and found Shadow. Seeing that Shadow was after Eggman Nega too, Sonic challenged him to see who got to Eggman Nega first. Sonic eventually outraced Shadow and found Eggman Nega, and demanded to know his plan. Eggman Nega however, retaliated by unleashing Metal Sonic on Sonic. After defeating Metal Sonic, Sonic thought about Eggman Nega’s plan, but ran into Silver again. 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 chased the doctor again.

Sonic and Silver eventually cornered Eggman Nega and Sonic demanded Tails’ card back, but Eggman Nega fought him and Silver with the Egg Lynx. After defeating the Egg Lynx, Sonic reclaimed Tails’ card while Eggman Nega escaped. Sonic then freed Tails from his card, but then Knuckles reappeared and Sonic was challenge by him to race to Eggman Nega first.

Sonic eventually reached Eggman Nega first where he faced 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 and escaped, much to Sonic’s frustration. Tails however, appeared in the Tornado and they traveled to Eggman Nega’s base. As Sonic ventured to and through Eggman Nega’s base, he met Knuckles, Shadow and Silver, and they each put aside their differences to help stop Eggman Nega.

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 world into a card. Sonic then noticed that Eggman Nega planned to fuel the device with Amy’s card and some other cards, but the four rivals destroyed the spaceship as it took off, thus foiling Eggman Nega’s plan. After the battle, Sonic freed Amy from her card, who believed this meant that Sonic and Amy were to live happily together. Sonic however, came up with the excuse that he had to find the other captives in Eggman Nega’s cards and ran off.

Sonic Rivals 2
In Sonic Rivals 2, Sonic arrived on an island to meet Tails who told Sonic that a group of Chao have gone missing and that he suspected Dr. Eggman, who was on the island, was behind it. As such, Sonic teamed up with Tails to find Eggman and get answers. No sooner, Sonic saw Knuckles with Rouge and teased Knuckles. Regardless, Knuckles asked if he had seen Dr. Eggman since the Master Emerald had been stolen. Unsurprised, Sonic insisted on finding Dr. Eggman first and the two competed to see who would find the doctor.

Sonic and the others eventually found Dr. Eggman, who really was Eggman Nega masquerading as Dr. Eggman (Sonic does not realize this throughout the game). Sonic demanded to know what he had done with the Chao, but Eggman Nega pretended to be innocent and attacked Sonic and the others in his Egg Liner. After the fight, Sonic and Tails followed Eggman Nega to Sunset Forest Zone. As they lost the doctor's trail, they found a page dropped by Eggman Nega mentioning a creature called the Ifrit. Soon after, Sonic ran into Silver, who was looking for Eggman Nega as well and challenged him to see who faced Eggman Nega first.

Sonic and Tails eventually caught up to Eggman Nega with Silver and Espio, but Eggman Nega attacked them in his Egg Crawler. After the fight, Sonic and Tails followed Eggman Nega to Neon Palace Zone where they lost track of him, though they found more dropped pages on the Ifrit. While in the city, Sonic met Shadow and Metal Sonic. Suspicious at why Metal Sonic was involved, Sonic and Tails followed the pair, with Sonic following Shadow. After catching up with Shadow, Sonic began questioning him, but the two fought when Shadow refused to answer. After the fight, Sonic and Shadow found Eggman Nega who attack in his Egg Dealer, but the group defeated him.

Afterwards, Sonic and Tails tracked Eggman Nega to Frontier Canyon Zone, where they found more dropped pages on the Ifrit, and Sonic suspected it was involved in Eggman Nega's plans. They then met Knuckles and Rouge again, who needed Rings to fuel their Emerald Detector, and Sonic volunteered himself and Tails to find some. After Sonic had found enough Rings however, Espio appeared and took them, but Sonic pursued him. Afterwards, Sonic found Eggman Nega again and demanded to know his plan, with the doctor saying that he had to beat his Egg Bull for that. Despite interference from Silver and Espio, Sonic and Tails destroyed the machine, and the doctor revealed his plan to release the Ifrit from a portal within a haunted mansion and Sonic and Tails headed there to stop the Ifrit.

At the mansion, Sonic and Tails split up. While searching, Sonic met a shape-shifting ghost of himself and defeated it in battle. After reuniting with Tails, they found Eggman Nega with their ghost counterparts. After fighting Eggman Nega in his Egg Phantom, Tails found the missing Chao, which Eggman Nega had planned to feed to the Ifrit to make it invincible, and Sonic got Tails to bring them to safety while he searched for Eggman Nega.

The two 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. There, they faced the Ifrit itself, who took control of Tails, forcing Sonic to face both Tails and the Ifrit to stop the end of the world. The two friends defeated the Ifrit, thus keeping it from leaving its world and escaped before the portal closed. With the Ifrit stopped, the world safe and the Chao rescued, Sonic and Tails headed to the Chao Garden to get some rest.

Sonic and the Secret Rings
In Sonic and the Secret Rings, Sonic awoke from a nap when he 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. Willing to help, Sonic agreed to help Shahra and she lead him into her world. While on their way, 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 hit by 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. Sonic caught up to Erazor who was 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 Erazor's fate, Sonic wished for a mountain of handkerchiefs, allowing her to cry as much as she needed to. Afterwards, Sonic discarded Erazor's lamp in the Evil Foundry before looking for a way back to his own world, having many adventures along the way before finally going home.

Sonic and the Black Knight
In Sonic and the Black Knight, Sonic was apparently enjoying some chili dogs while waiting for Amy, having somehow been talked into going on a date with her. Suddenly, however, Sonic was called into the world of Camelot by Merlina the Wizard, in order to defeat King Arthur, who had become a tyrant after being corrupted by the power of the scabbard of Excalibur, which made him immortal. After a not-so-graceful arrival, Sonic met Merlina and quickly dispatched King Arthur's Knights of the Underworld who were following her along their King. Sonic then tried to take on Arthur, but he was restrained by Merlina, who teleported Sonic and herself away.

After retreating from King Arthur, Sonic was filled in by Merlina on the kingdom's situation and was lead to the Sacred Sword Caliburn, a sentient sword who would become Sonic's teacher in knighthood, to obtain a better fighting chance. After finding Caliburn, Sonic had a brief confrontation with King Arthur (who left because he did not consider Sonic a threat). Sonic and Caliburn then left to find Nimue, Lady of the Lake who knew how to stop the sabbard of Excalibur. During their search, Sonic met Sir Lancelot who was sent to kill him, but Sonic defeated him and took his Arondight.

Sonic and Caliburn eventually found Nimue, who told Sonic that she would only reveal the scabbard's secrets to him if he passed a test of true knighthood, and gave him three tasks to finish within three days time. Confident, Sonic told the concerned Caliburn that he would be a knight before long.

As Sonic and Caliburn worked on completing the tasks, Sonic met a young villager whose family and fellow villagers were kidnapped by a dragon. Following his heart, Sonic decided to help the child despite of Caliburn's protests. On their way to the dragon, Sonic encountered Sir Gawain, who had come to kill him, and fought him in battle. After beating Gawain, Sonic 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.

Eventually, Sonic saved 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 he had proven himself 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. Already having gather two, Sonic went to get the last one from Sir Percival. After not only defeating Percival, but also saving her life, Sonic earned Caliburn's respect and was titled "Sir Sonic, Knight of the Wind".

With all four Sacred Swords, Sonic faced King Arthur and defeated him, only to see him vanish like his minions. As Sonic returned with the Scabbard of Excalibur to Merlina, she revealed that she had used him so she got get the scabbard 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 assault, and they united 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, 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 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 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 thought it was an excuse for forgetting their date, 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 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 achieve his Super State, 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.

Sonic Unleashed
In Sonic Unleashed, after an untold series of adventures for Sonic, 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.

Sonic turned into Super Sonic, destroying Eggman's mech and his fleet 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 "Werehog". 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. Sonic and Chip then caught up to Eggman and defeated him before 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 as a Werehog, 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 at 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 collapsed 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
In Sonic the Hedgehog 4: Episode I, which takes place directly after the events of Sonic & Knuckles, Sonic had just 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, when Dr. Eggman revealed himself to be alive after their last encounter and had returned to defeat Sonic for good with a new and improved army of Badniks.

Sonic then began chasing and fighting Dr. Eggman while collecting Chaos Emeralds through 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 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 before confronting the mad scientist's 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.

Sonic remained certain 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. 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 defeat 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 Nega-Wisp Armor, determined to crush 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 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, in the past of Green Hill, Sonic's younger self, Classic Sonic, was exploring until he heard a noise and noticed the Time Eater in the sky before everything turned white. In the present day, a while after Sonic's adventures in Dr. Eggman's Incredible Interstellar Amusement Park, Sonic's present self, Modern Sonic, arrived at a picnic and found his friends holding a surprise party to celebrate his birthday, which Sonic delightly joined. As Modern 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.

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 each other 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 Time Eater and restore time, space, reality and their friends.

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 that he had a great future ahead of him.

Sonic Lost World
In Sonic Lost World, Sonic and Tails were chasing after Dr. Eggman, Orbot and Cubot on the Tornado to free some animal friends they have captured. Eggman dropped the capsule containing the animals from the sky, forcing Sonic and Tails to go after it. As Sonic and Tails tried to free the animals, the Tornado was damaged by Eggman's laser, forcing Sonic and Tails to fall on the Lost Hex, which they discovered during their descend.

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 to. Not long after, Sonic was attacked by Zazz, but defeated him. Soon after, he found Dr. Eggman, who introduced the Deadly Six - Zazz included - a group of Zeti that he controlled, to him. As Eggman then left Zazz to finish him, 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 and defeated Zomom twice. Soon after, Sonic and Tails snuck up on Eggman when he was scolding the Deadly Six. Noticing that Eggman used a conch to control the Deadly Six, Sonic knocked the conch away. This proved to be a mistake, however, as the Deadly Six then rebelled against Eggman by talking control of his Badniks and using them to attack everyone present. When Tails got injured in battle, Sonic left to take Tails to safety, escaping with Eggman, Orbot and 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. After Sonic defeated Master Zik, he and Tails was contacted by Amy, who informed them that something was sucking the life out of the world. After another battle with Master Zik, Sonic and Tails met Eggman again, who revealed that the Deadly Six were using his Extractor to drain Earth of its energy to make themselves stronger until the planet was destroyed, which Sonic saw matched Amy's report. Sonic then reluctantly agreed to team up with Eggman and bring the doctor to the Extractor and have him shut it down properly.

Arriving at Eggman's factory, Sonic discovered that Tails was mad at him for trusting Eggman more than him to stop the Extractor, and tried fruitlessly to defend himself. After fighting Zeena, Sonic and the others were briefly contacted by Zavok, who stated the futility of their actions. After another fight with Zeena, Sonic rebuffed Eggman's plan to kill the Deadly Six by destroying the Lost Hex along with countless innocent, when Tails got attacked by Cubot when he put his head on a Crabmeat. Eggman, however, saved Tails, leaving Sonic confused by Eggman's 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, discovering that it was a trap set by the Deadly Six. Sonic then witnessed Tails getting caught and teleported away, leaving Sonic ridden with guilt for his inability to save him. Soon after, Sonic met Zor and demanded Tails back before fighting him, though Zor managed to escape.

After getting to Sky Road, Sonic met Zavok and was horrified to hear from him that he planned to turn Tails into a robot, before fighting and defeating Zavok. Continuing forward, Sonic 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, leading to Sonic battling and defeating Zavok again.

When Sonic and Eggman arrived at Lava Mountain, they were attacked by Zazz and Zomom, who destroyed the bridge Sonic and Eggman stood on and nearly fell into a lava pit. Sonic, however, was saved by Eggman, who threw him back on ground while Eggman himself fell into the lava pit. After escaping, Sonic faced and defeated Zazz, Zomom and Master Zik for good. Sonic then unsuccessfully tried to contact Amy and Knuckles, and was disheartened to see that he was now all alone. Soon after, Sonic met Zavok, Zeena and Zor, and saw to his horror and anger that Tails had seemingly been turned into a robot. When Tails was ordered to kill Sonic when he refused to serve them, however, Tails revealed that he only pretended to be a robot and attacked the Zeti. Relieved to have Tails back, Sonic fought and defeated Zeena, Zor and Zavok for good.

Having finished the Deadly Six, Sonic and Tails got to the Extractor, where they discovered it was already turned off. Eggman then showed up in a new mech, having faked his death so that he could charge his mech while Sonic fought the Deadly Six and now planned to conquer what was left of the world, but Sonic fought and defeated Eggman's mech. As Tails reprogrammed the Extractor to return the world's energy, Sonic, who realized that Eggman was not needed, apologized to Tails for doubting him, mending their friendship. When Eggman then tried to escape using his jet pack, Sonic revealed to him that he had removed its exhaust pipe, causing Eggman to fall down from the Lost Hex. After returning the world's energy, Sonic and Tails returned to Earth and met up with Knuckles and Amy. Glad for the adventure to be over, Sonic lay down in the grass to take a nap.

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.
 * Have Sonic join the player's party in the Subspace Emissary.

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.

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

Super Smash Bros. for Nintendo 3DS/Wii U
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.

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.

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.

Sonic the Hedgehog (TV series)
In the Sonic the Hedgehog television series, 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 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. After many battles and gorilla tactics, Sonic and Sally defeated Robotnik when the doctor launched his Doomsday Project.

Sonic Underground
In Sonic Underground, 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. 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 Earth. Shortly after arriving, Sonic nearly drowned in a pool, but was saved by Christopher Thorndyke, who Sonic became friends and lived 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 conquer this new world. 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.

Six months after coming back home, 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 galaxy. Upon returning to his home planet, Sonic had his goodbye with Chris who left 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 Sonic Boom, which will air in Fall 2014, and its video game.

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 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 Sonic the Hedgehog comic book series and its spin-offs published by 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 Dr Ivo Robotnik 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 problems between his friends and political troubles on the homefront. Following the disbandment of the Knothole Freedom Fighters, Sonic assumed leadership of Team Fighters to continue fighting Dr. Eggman. When the second Genesis Wave was unleashed, Sonic teamed up with Mega Man to bring their universes back to normal, though the timeline of Sonic's universe became distorted in the process.

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 the world in search of adventures. He has a strong passion for enjoying life, 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 while enjoying his freedom.

Sonic is most of the time laid-back, carefree, cool and enjoys relaxation. However, he is often impatient and frustrated with slower things, and has a short temper. Because of his impulsive nature, Sonic can be reckless and quick to act before thinking, throwing himself into the middle of trouble without a second thought and regards to other's warnings.

Because of his need for freedom, Sonic loathes the idea of being constrained. He is very much addicted to action and running, and being held captive makes him twitchy and act absurd, such as in Sonic Adventure 2 where he could not stand being held up in a tiny prison cell.

Sonic's personality is a juxtaposition of kindness and ferocity. He is extremely benevolent and firmly stands for freedom, but he is never the one to rest in the face of injustice or oppression. He hates evil in all its forms, being easily riled up about it when witnessing injustice, oppression, or other's despair, and will do all in his power to snuff it out. At the same time, Sonic has a big and kind heart and possesses a lot of righteousness. He is fully committed to helping out those in any kinds of trouble however he can, even if his actions will be met with contempt or have consequences, and cannot look away when somebody else is in trouble. He always keeps his word and is willingly puts himself at risk to help others, taking on any challenge that confronts him without hesitation, though he usually sees his heroics and fighting evil as an opportunity to have fun, making him somewhat of a thrill-seeker and enjoys any challenge that passes him. However, in times of crisis, he focuses intensely on the task at hand as if his personality had undergone an astonishing change.

Sonic has a lot of self-confidence and possesses a large ego to match it, making him sassy, cocky, quick-witted and sometimes overconfident in his abilities. He has a lot of attitude, shows a lot of sarcasm through his gestures and has a narcissistic tongue. He often jokes around to light the mood, but will also take any opportunity to taunt and mock his opponents, and takes many of the lesser situations he faces lighthearted. He is also not generally modest when it comes to his abilities and is very proud of his skills, smug and a showoff. On the other hand, Sonic can also be quite the gentleman when he wants to, showing modesty when taking compliments and having good manners, and he mainly prefers to simply be called by his name and not by any fancy title.

Following his free-spirited nature, Sonic never dwells on the past or allows his loses or hurtful experiences to weight him down. Instead, he choses to live in the present and always looks forward to his next adventure, while holding no regrets for whatever has transpired.

Sonic is extremely loyal to his friends and is willing to put his life on the line for them without any due consideration. Though he sometimes teases them or acts rude, he cares generously for all his friends and if they are in danger, Sonic will put them above all else at hand. While he can leave them hanging or even endanger them due to his fast-paced nature, Sonic has never has any intention of making them unhappy. Equally, Sonic is always willing to accept help from his friends if offered, and will show great trust in them, though he is not above making mistrusting assumptions of them. Despite his devotion to his friends, however, after spending time with his friends, he seeks some alone time and relaxation, but will always back to them sooner or later.

Sonic known for having an indomitable will and a lot of stubbornness. He is incredibly strong of character, possessing a never-waving faith in himself and never gives in to his own weaknesses. Also, no matter what happens or who looks down on him, Sonic always preservers, never quits or submits, and will do whatever it takes of him to save the day.

Regardless of the countless foes he has fought throughout the series, Sonic rarely bears a noticeable ill will to any of them, but rather admires them for how powerful some of them are and how much fun they have given to him. Likewise, Sonic is shown to have a remarkable capacity to forgive, forgiving Silver and working with him after he had tried to kill him twice.

Despite his thrill-seeking, hyperactive and smug demeanor, Sonic has shown to be much more insightful than he usually lets on, such as in Sonic Adventure, where he saw that simply resealing Chaos in the Master Emerald while Chaos was still suffering from all of its rage would solve nothing in the end. He was also able to give Elise valuable and comforting advice in Sonic the Hedgehog (2006), and in Sonic and the Black Knight, he was able to give Merlina similar words of encouragement and comfort. Also, Sonic can also be quite observant in regards to other people's feelings, such as when he was able to see that Blaze had a rough past when she insisted to keep fighting to to protect the Sol Emeralds. 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.

A very noticeable trait of Sonic is his fondness of the beauty of nature, and he stands as a protector of it. He appreciate scenic views, and in Sonic Colors, he showed an emotion of anger and rage when he found out that Eggman was polluting Planet Wisp's beautiful environment. In Sonic the Hedgehog (2006), Sonic is also shown to have a fondness for locations that are filled with flowers, trees and other kinds of plants.

Sonic has been shown to enjoy music, but seems to have an special interest in rock music. 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 numerous games usually when he is victorious.

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). 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, though it is on various occasions assumed that he can. In Sonic Battle, it is stated that he can move several times the speed of sound and when the Final Egg Blaster was about to fire, Sonic defeated Ultimate Emerl in less than 30 seconds. It is also believed that Sonic can move faster while in spinball form than running, possibly even reaching the speed of light as seen in Sonic Adventure, Sonic Adventure 2 and Sonic Heroes where he could utilize the Light Speed Attack and the Light Speed Dash to achieve light speed movements. Also, in Sonic Unleashed, the Checkpoints, which measure his speed (SPD) in-game, can clock Sonic going over 2,800 SPD; in comparison, the Light Speed Dash measures 396 SPD, meaning Sonic is approximately seven times faster than the Light Speed Dash. Since the Light Speed Dash peregrinates 670,616,629 mph (1,079,252,848.18 km/h), it makes Sonic's approximate speed over 4 billion mph (6 billion km/h).

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 additionally shown to be able to run in full tight circles, thus is not exposed to the impotency of only being able to run fast in straight lines. Should he be running at uncontrollable speeds, he can utilize the Drift to opportunely control his momentum and even crash into foes with it.

Aside from using it to run, Sonic can also apply his super speed for other abilities. He is able heal himself by vibrating his body at supersonic speeds, and he can launch shockwaves of air by spinning in his spinball form at high speeds.His top speed still remains unknown, and Sonic has never shown any limits of his speed.

Physical Abilities
In line with his super speed, Sonic has exhibited astounding feats of kineticism, precision and has the reaction time to match. He possesses great acrobatic skills and agility, alongside astonishing reflexes, making him able to avoid sizably voluminous and minuscule obstacles with precise jumps and delicate movements despite the speed they are approaching at, along side double jumps and wall jumps. When launched into the air, he can also perform several airborne tricks before landing on ground. He also has incredible jumping skills, allowing him jump up to several hundred meters, possibly by applying speed to his jumps.

In terms of physical vigor 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 genuinely 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 at high speed (such as carrying Tails to safety in Sonic Lost World), and his Spin Dash and other spin forms are strong enough to cut through metal, 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 strong though; in Sonic the Hedgehog CD, Sonic exhibited strength great enough to tear robots apart 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 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 surrenders. 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, and do have more abilites prior to chaos control.

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 with far more battle experience. 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.

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, and in Sonic CD, it shows that The Super peel Out can push Sonic out extremely fast speeds.

Another technique, the Blue Tornado 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. Sonic Wind is when Sonic creates a cyclone of blue swirling winds and fires it at the opponent.

One of Sonic's newest signature moves is the Sonic Boost, a technique where he can increase his speed further, envelope in blue aura 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 and can use it to practically fly immense distances through midair.

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.

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).

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 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 is able to transform into Excalibur Sonic by using the power of the four 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 Sacred 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 is incapable of swimming and sinks like a stone in water, which may be due to aquaphobia. A slight exception being in Super Smash Bros. Brawl where he is able swim very briefly before drowning. In some games Sonic can bypass water while running across its surface, while in others he can survive extended periods underwater by breathing air bubbles, in most 3D games however he drowns instantly on contact with water. Sonic usually avoids water and in Mario & Sonic at the Olympic Games and Mario & Sonic at the London 2012 Olympic Games, Sonic is the only character to wear a life-preserver.

Yuji Naka stated that Sonic can not swim because previously SEGA thought that hedgehogs could not swim, and that if Sonic does not sleep for eight hours during the night, it would spoil his running.

Relationships
In the games, Sonic has encountered many people and thoughout his adventures, he has received 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.

Doctor 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".

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.

There have been a few games where Eggman joins Sonic and his friends and allies to stop a more terrible threat. In Sonic Adventure 2, the main characters learnt that Gerald Robotnik planned to have the ARK crashed onto Earth, destroying it in the process. Upon finding that out, Eggman works with the heroes to stop the ARK's collision cource with Earth. In the last story of Shadow the Hedgehog, Eggman appears with most the supporting characters (including Sonic), it is possible that Eggman learned that Black Doom and his army were planning to do something to the Earth, and so, Eggman decided to work with Sonic again to help Shadow. In Sonic the Hedgehog (2006), Eggman is brought to the distorted world (created by Solaris) along with many of the game's main characters. After Silver resolves to revive Sonic with the Chaos Emeralds' power. Eggman helps the group by using his glasses to locate the Emeralds and tells them that the Emeralds are scattered around the dimension. In Sonic Lost World, Eggman is betrayed by the Deadly Six early in the game due to Sonic's actions. Eggman decides to work with him and Tails to stop the villainous Zeti. Once all of the Deady Six are disposed of, Eggman, in a surprising turn of events, betrays Sonic and Tails.

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.

Tails grieved over Sonic's "death" in Sonic Adventure 2 after he saw a capsule that Eggman had launched with Sonic in it explode, he took his anger on Eggman by fighting him with Tails winning the battle. When Sonic rejoins with Tails, he was relieved to see Sonic still alive.

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 asks Tails 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 Tails was close to getting shot by 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 in his heart, 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 "Wait, Why do 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. Amy (along with Sonic's other friends) appears in the center of time, saying to Sonic "You can do it Sonic!" in order to give him strength against the Time Eater.

Metal Sonic
Sonic and Metal Sonic have a violent rival/enemy relationship. Eggman created Metal Sonic in order to defeat the real Sonic, believing 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. 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 Orange 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 and argued every time they cross paths, even sometimes trying killing each other. 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 affects. Nevertheless, they do not care of each other's views and see this 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 becoming 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, going 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 skills, 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. 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.

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 also seems to rely on Sonic the most and has respect for both him and his skills 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 world 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 the Hedgehog (2006) 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 rival who wants a friendly fight. He also appeared at the Center of Time after Sonic was knocked out by the Time Eater, Silver says to Sonic: "I know you can do this Sonic!".

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 taunting 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, 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, 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 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 for excitement and fun. However, even when determined to beat Jet, Sonic does not wish to have any unfair advantages, and is willing to give Jet both the chance to prove himself and face him at his best. Despite how many times they face each other, Sonic always looks 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 and sidekick, close as brothers)
 * Amy Rose (self-proclaimed girlfriend)
 * Knuckles the Echidna (best friend and rival)
 * Vector the Crocodile
 * Espio the Chameleon
 * Charmy Bee
 * Big the Cat
 * Shadow the Hedgehog (ally and 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)
 * Princess Elise (in Sonic the Hedgehog (2006) only)
 * Shahra
 * Merlina
 * Shade the Echidna
 * Chip (good 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

 * Dr. Eggman (arch-enemy)
 * Metal Sonic (robotic doppelgänger)
 * Dr. Eggman Nega
 * Shadow the Hedgehog (sometimes)
 * Fang the Sniper
 * Pir'Oth Ix
 * Shade the Echidna (former)
 * Chaos (former)
 * Biolizard
 * Solaris
 * Dark Gaia
 * King Arthur
 * Merlina the Wizard (former)
 * Erazor Djinn
 * Nega-Mother Wisp
 * The Deadly Six
 * Black Doom

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.

Solo Themes

 * In Sonic the Hedgehog 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."
 * In Sonic Adventure 2, Sonic's theme is a a faster-paced, alternative rock remix of "It Doesn't Matter."
 * Also, in Sonic Adventure 2, the City Escape stage has lyrics to the music, which refers to some of Sonic's traits.
 * 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

 * In Sonic the Hedgehog CD, Sonic's fur was a lighter shade of blue.
 * 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 the Hedgehog 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.
 * 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. 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 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.
 * 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 known 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 former 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 shown 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 (or Jet Set Radio), one of the characters, Garam, wears a necklace with a skull on it. In an GamesTM interview with the art director of that game Ryuta Ueda, he stated that it is Sonic's skull in which Ryuta hinted that it's a skull of "another famous Sega character."
 * Miku Hatsune, a Vocaloid, who is 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.
 * In the Archie Comics, Bean the Dynamite always refers to him as Mr. Needlemouse, Sonic's original name.
 * 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.
 * In recent games, Sonic has been shown with detailed fur.
 * In the early concept of Sonic, Sonic was supposed to have a rock-band, and a girlfriend named Madonna but the idea was later scrapped.