Sonic the Hedgehog

"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 15-year-old blue anthropomorphic hedgehog gifted with the ability to run at the speed of sound and beyond, hence his name, and possesses lightning fast reflexes to match. As his species implies, Sonic can also roll up into a concussive ball, primarily to attack enemies.

Ever since stepping into the battle against injustice, Sonic has been the champion of peace and is renowned the world over for saving it countless times. During his many adventures, Sonic has traveled from the ends of the world to the far reaches of space and time, while facing countless trials that have tested him to the fullest, earning him many titles, allies and the scorns of several foes. Well-known for his legendary cocky attitude, easy-going demeanor and somewhat short temper, yet strong sense of justice, compassion, heart of gold and love for freedom and adventure, Sonic uses his abilities to protect the innocent from his world and those beyond from the forces of evil, especially his arch-nemesis Dr. Eggman, who constantly seeks world domination.

Sonic has been acknowledged as, undoubtedly, 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 a separate Sega character, 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. According to Yuji Naka, Sonic's color also serves to symbolize peace, trust, and coolness which are the attributes of Sonic's character. His trademark speed is based on Super Mario Bros. World 1-1, with Sonic creator Yuji Naka stating in issue 260 of Nintendo Power that "I always tried to get through the level as fast as I could,"'' which inspired the initial concept for Sonic the Hedgehog. 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 fifteen-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 except that he was born on Christmas Island with the innate ability to run at super speed, but his love for adventure eventually called him away from his home. Since then, he has spent his life traveling around the world, driven by his restless spirit, in search for adventure to satisfy his thirst for thrills.

At some point, Sonic met Dr. Ivo Robotnik and they became enemies under unknown circumstances. Following their meeting, Sonic fought Dr. Robotnik in an untold number of confrontations as the scientist attempted time and time again to conquer the world, with Sonic each time 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 Dr. Robotnik invading South Island after the doctor had discovered some powerful relics, called the "Chaos Emeralds", which were hidden on the island and which he now sought to produce weapons of mass destruction with their power. 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: trapping them inside robot shells. With this method, he could turn them into robotic servants called Badniks, 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 local stronghold, where he defeated the mad scientist and drove him off the island. With Robotnik defeated, Sonic reunited with his friends to Green Hill Zone, where he released the Chaos Emeralds, with their power ensured the island's prosperity.

Mega Drive
In Sonic the Hedgehog 2, Sonic was traveling the world in the Tornado in search of adventure, when he discovered West Side Island. Deciding to take a rest there, Sonic landed on West Side Island and began exploring this new region. After a few days though, 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. As Tails dashed into the shade of a nearby tree upon being discovered, Sonic chose to ignore him and tried running away, but Tails continued to follow him and even kept up with his speed. Impressed by the fox's tenacity and ability to keep up, Sonic decided to let him tag along despite his disinterest in him.

Later, during an early afternoon, Sonic was taking a nap under the shade of the Tornado's wing when he was awoken by explosions and saw Badniks attacking West Side Island. Standing beside Tails, who was watching him, during the initial attack, Sonic furiously knew that Dr. Robotnik was behind this and ran 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 located on the island, to create the Death Egg so that he could conquer the world. Sonic therefore took off to stop Robotnik, retrieve the Chaos Emeralds, and save the island, with Tails following him all the way. When Sonic obtained all seven of the Chaos Emeralds, he discovered that their powers could turn him into Super Sonic. All the while, Tails proved to be great assistance to Sonic with his unique skills, and the two began forming a strong bond.

After freeing West Side Island, Sonic and Tails followed Robotnik to the Wing Fortress Zone on board the Tornado. As soon as Sonic stepped onboard, however, Tails and the Tornado were shot down, forcing Sonic to go on alone. When Dr. Robotnik escaped in his rocket ship, Sonic found Tails coming to his aid in an rocket-enhanced Tornado. Catching up to the doctor's rocket in the Tornado, Sonic grabbed onto it and rode with it to the Death Egg. There, Sonic fought Robotnik's Mecha Sonic, followed by Robotnik 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, but Sonic escaped by jumping off into space just before the Death Egg exploded.

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. With their adventure coming to a close, Sonic had become best friends with Tails and accepted the fox as his sidekick which would set the course for his future.

Game Gear/Master System
In Sonic the Hedgehog 2, Sonic had become bored out of his mind as South Island had been peaceful since he defeated Dr. Robotnik. He therefore decided to go on a journey in search of other adventures, but upon his return, he was shocked to find the island nearly abandoned. The only clue Sonic could find as to where all his friends could have disappeared to was a single note, written by Tails. In the note, Tails explained that he and the animal friends had been kidnapped by Dr. Robotnik and were being held in a place called the Crystal Egg. In exchange for Tails' safe return, Sonic had to collect the Chaos Emeralds, which were to be delivered to Robotnik's six Master Robots. With no time to waste, Sonic immediately set off to save Tails.

Along his adventure, Sonic collected the Chaos Emeralds as instructed while destroying the Robot Masters one by one during each encounter. At the time Sonic had gotten five Emeralds and destroyed five Master Robots, Sonic met the final Robot Master, Silver Sonic which he destroyed too and claimed the final Chaos Emerald from its remains. Sonic went on and faced Robotnik in the Crystal Egg Zone, but the doctor escaped through a teleporter upon his defeat. With Tails still missing, Sonic almost despaired, but then Tails appeared from the teleporter, unharmed. Though confused at this turn of events, Sonic was happily reunited with Tails and the duo departed for new adventures together.

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, only to be blown to the other side of the island with Mighty and Ray by a geyser triggered by Robotnik. Working together to escape the island, the trio got to Eggman's Tower where they confronted Robotnik. Robotnik, however triggered the self-destruction of the tower, 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 goes near Earth once a year, to explore it. 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, Sonic noticed Dr. Robotnik's face carved into the mountain where the chain was embedded; immediately he knew that his arch-nemesis was behind this and up to no good again. Sonic therefore traveled to the Little Planet to liberate it from Robotnik'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 Amy Rose, Sonic's biggest fan and want-to-be girlfriend, who was on the planet in hopes of meeting him. However, Sonic was far from excited to meet her. Only shortly after Sonic met Amy, 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 escaped with Amy, Sonic now had the task of saving Amy as well.

Using his unrivaled speed, Sonic managed to 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 raced Metal Sonic at Stardust Speedway. At the end of the race, Sonic was victorious, while Metal Sonic was left severely damaged. Sonic also saved Amy from captivity.

Sonic went on and defeated the doctor in a final battle at Metallic Madness. With Robotnik's defeat, the doctor's bases began exploding. Sonic escaped them, and the Little Planet, safely, along with Amy. 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 warping away, 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 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 is 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 the Chaos Emerald in his possession, ensuring South Island's safety once more.

Sonic the Hedgehog 3
In Sonic the Hedgehog 3, many days after the events of Sonic the Hedgehog 2, 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 reaction.

When Sonic and Tails arrived at the location, they found the legendary Angel Island, which was 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 and Tails set out to stop Robotnik from relaunching the Death Egg.

As they neared the island, Sonic used the Chaos Emeralds 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, forced the Chaos Emeralds out of Sonic, which returned him 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 emeralds.

Despite this setback, Sonic and Tails headed out to to liberate the island from the control of Dr. Robotnik's robots and destroy the Death Egg for good. 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. Therefore, Sonic 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 were 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. Riddled with questions, 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, they saw that Robotnik was stealing the Master Emerald for the purpose of powering the Death Egg. Thus, 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, which was powered by the Master Emerald. Sonic and Tails managed to defeat the contraption, which finally destroyed the Death Egg for good. However, 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, Sonic and Tails caught wind that Dr. Robotnik had lost the Chaos Emeralds following a weapons test and sprung into action to find them before Robotnik could. While they collected information 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 and told Sonic that he would never get the Emeralds before leaving. 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 retrieve 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 sneaked up on him while Sonic was unaware, Dr. Robotnik proclaimed 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. He soon after realized that he could still use his Spin Dash to move 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 made him flee from the island, while regaining the Chaos Emeralds and his regular shoes as well.

Sonic the Fighters
In Sonic the Fighters, Sonic learned that 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, which could fly its pilot directly to the new Death Egg to destroy it. However, 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, Sonic included, and as well earn the right to go to the Death Egg II and destroy it.

At the end of the tournament, the victor got all the Chaos Emeralds and used them to go to the Death Egg II in the Lunar Fox. There, the victor defeated both Metal Sonic and Robotnik using the Emeralds and rigged the Death Egg II to self-destruct before heading back to Earth in the Luna Fox moments before the massive space station exploded.

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, turning the Flickies into Badniks. 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 could power his robots and be used to find the Chaos Emeralds, which were located on the island. Once Sonic made 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, along with his robot lackeys, who 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. In the end though, Sonic managed to keep his title as the fastest thing alive while he and the others kept Dr. Robotnik from getting his hands on the Chaos Emeralds.

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. While traveling through Station Square, he saw the Station Square Police fighting Chaos. Sonic stepped and defeated Chaos, though it escaped. The following day, Sonic was taking a nap when he saw Tails' crash in his newest plane.

As Sonic came to Tails' rescue, the fox revealed he was working on a new aircraft powered by a Chaos Emerald. Sonic traveled with Tails to his workshop to see his 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 set out with Tails to get the Chaos Emeralds before Dr. Eggman could give them to Chaos.

Eventually, Sonic and Tails got two Emeralds from Windy Valley and Casinopolis. After leaving Casinopolis, however, Dr. Eggman appeared and hit them with sleeping gas while stealing one of their Chaos Emeralds. Unshaken, Sonic and Tails continued their search. After finding another Chaos Emerald, 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, 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, however, the Tornado was shot down.

After landing near Station Square, Sonic began looking 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, who eventually kidnapped Amy, and Sonic took off to save Amy.

Sonic corned ZERO in Mystic Ruins, but it to escape with Amy to the Egg Carrier. Sonic pursued the Egg Carrier 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 found Amy on the bridge, Sonic 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. 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 to save Froggy who was trapped inside Chaos and Sonic promised to help. After saving Froggy, Sonic defeated Chaos 6, only for Knuckles to appear as Eggman escaped. Leaving Chaos to Knuckles, Sonic chased Eggman into the Mystic Ruins, where he found an ancient temple and a mysterious light. Inside the temple, 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 defeated the doctor for good. 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. When they got 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. Sonic and Tails were then about to head out to get the last Chaos Emerald in the Tornado 2 before Chaos, when Sonic was drawn into the past again, where he saw the Knuckles Clan's attack on the Altar of the Emeralds, the event that drove Chaos to destroy the world 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. 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 Chaos' anger. 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. 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, 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 destroy Maginaryworld. With everyone in agreement, Sonic promised to help Lumina. Setting out in their mission, Sonic, his friends and Lumina began recovering the Precioustone pieces from the different worlds within Maginaryworld and restoring the places affected by Void. Whenever they got a Precioustone, Sonic and his friends had a dream where he met Void. In these dreams, Sonic and the others 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 sought 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. Having cheered Lumina up, Sonic handed Void over to Lumina and witnessed her 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 receive Illumina's gratitude, before they 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. Handcuffed, Sonic was brought onboard a military helicopter, but while over Central City, Sonic successfully escaped.

After escaping, Sonic encountered Shadow the Hedgehog, the true thief of the Chaos Emerald. Realizing that he had been mistaken for Shadow for the theft, Sonic attacked him, but Shadow used Chaos Control to escape. No sooner, Sonic was surrounded by G.U.N. 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 and as well that Shadow was on the island and Dr. Eggman was behind it all. With this information, Sonic left to find Shadow once Amy freed him. Once he found Shadow, Sonic fought him until he heard that the island was about to explode over Eggman's radio. Sonic, however, found Tails and Amy and escaped the island 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, powered by six Chaos Emeralds, by blowing up half of the Moon, before demanding total world control within 24 hours or he would fire the cannon at earth. As the police arrived, Sonic distracted them to give Tails time to track Eggman. He eventually contacted Tails and heard 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.

With Knuckles' help, Sonic, Tails and Amy found Eggman's base where they hoped to find a space ship that could take them to the ARK so they could destroy the Eclipse Cannon. After infiltrating the base, Sonic enlisted Knuckles to find the keys to enter the center of the base. In the center, however, they were ambushed by Eggman and his Egg Golem. However, Sonic defeated the robot and joined the others in a space shuttle.

While en route to Space Colony ARK, Knuckles tried to take control of the shuttle when a stray asteroid force-open the cargo bay and released his Emerald Shards, causing Sonic and the others 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 got to the cannon control room, however, he was contacted by Dr. Eggman, who demanded the final Chaos Emerald or he would kill Amy.

Meeting with Eggman, Sonic thought he could trick him into taking the fake Emerald. Eggman, however, saw through this and Sonic was captured in a capsule set to explode and rejected 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 got Knuckles to 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 destroyed the Eclipse Cannon just before it fired.

After the Eclipse Cannon was stopped, Sonic and Knuckles met Rouge, who revealed the ARK was on a collision course towards earth. Sonic and all the others then witnessed a recording of Gerald Robotnik announcing to the world that the ARK would crash into the planet and destroy it as his revenge at the world for the death of his granddaughter, Maria. Banding together with Eggman, Sonic and 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 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 they defeated the Finalhazard. The duo then stopped the ARK by sending it back into orbit with Chaos Control. Coming back on board, Sonic informed the others that Shadow had seemingly died after stopping the ARK, before giving Shadow's Inhibitor Ring to Rouge and assuring her that Shadow was a great hero. After processing Shadow's death, Sonic suggested that they all went back home and he 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. Over the course of their adventure, Sonic and his friends got the Chaos Emeralds first and followed Eggman to the X-Zone. After they defeated the EGG X, Sonic chased after Eggman as the scientist fled to the Moon. Sonic used the Chaos Emeralds to transform into Super Sonic and pursued him. On the moon's surface, Super Sonic defeated Eggman and his Super Egg Robo. After the fight, Super Sonic seemingly disappeared, but then reappeared a few days later 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 when he tried again to build the Eggman Empire. As such, Sonic headed out to save his friends. Along the way, Sonic met Cream the Rabbit and Cheese, who where held hostage by Dr. Eggman. After saving Cream and Cheese from Eggman, Sonic tried to leave them, but the duo followed him as Cream wanted to save her mother, Vanilla, who was held captive by Eggman too.

Following that, Sonic rescued Tails and Knuckles from Eggman (the latter who had been tricked by Eggman into fighting him) who also joined him on his adventure. After hunting down and seemingly defeating Eggman, Sonic and the others found Vanilla, only to have her kidnapped by Eggman in his new mech. Seeing Cream cry at the loss of her mother, Sonic transformed into Super Sonic and both defeated Eggman and saved Vanilla.

As they fell through the atmosphere, Super Sonic tried to break the fall of the capsule containing Vanilla, but the re-entry tore the capsule apart and Super Sonic powered down to normal. However, Sonic caught Vanilla 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 before running off again, looking for new adventures.

Sonic Advance 3
In Sonic Advance 3, while hanging out with Tails, Sonic witnessed Dr. Eggman splitting Earth into seven regions with Chaos Control and planned to turn each region into a part of the Eggman Empire. Sonic then headed out with Tails to restore the world and collect the Chaos Emeralds before Eggman could.

During their adventure, Sonic and Tails met Knuckles, Amy and Cream who joined them. Along the way, Sonic also faced Dr. Eggman's newest creation, Gemerl, a rebuilt version of Emerl. After securing the seven Chaos Emeralds, Sonic and his friends made it to the Emerald Altar where they beat the Hyper EggRobo and used the Master Emerald to return the world to normal. Sonic then followed Eggman and Gemerl, until Gemerl betrayed Eggman, took the seven Chaos Emeralds from Sonic and transformed into Ultimate Gemerl. Sonic, however, took the discarded Chaos Emeralds and transformed into Super Sonic. Putting aside their differences to fight a common enemy, Super Sonic and Eggman joined forces and defeated Ultimate Gemerl.

With Ultimate Gemerl's defeat, Sonic passed out in the following explosion, but woke up back home 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 to 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, who began fighting them. However, Sonic used the fight as a distraction to escape Amy.

Team Sonic then arrived in Casino Park. After passing through the city, Team Sonic was attacked by Eggman's robot hordes, which they defeated. As they chased Eggman to Rail Canyon and only having until sunset, Sonic and his team reached Bullet Station and destroying Eggman's local base. There, the team found Eggman in the Egg Albatross and defeated him. However, Team Sonic then 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 to decide who went after Eggman. After the battle, Sonic saw Eggman and Shadow head towards Hang Castle and lead his team that way. After infiltrating the castle and escaping Mystic Mansion, Team Sonic was attacked by Eggman's robot hordes, but they quickly beat them.

After that, Team Sonic got to the Egg Fleet, where they traveled across the flagships to the Final Fortress and 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 and thanked both him and Tails for their help. No sooner though, Amy came running and Sonic tried to escape.

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 became 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 coming. Sonic then told Metal Sonic that he would be ready for a rematch anytime and left with Tails. Soon after, Sonic 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, helping Shadow fight 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, and asked for his help in taking out the enemy.

In the Hero scenario, where Shadow accepted Sonic's request, Sonic tried to chat with Shadow after completing their objective and suggest 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 found the Black Tank containing the Chaos Emerald the Black Arms had taken. As Sonic chased after the Black Tank, he met up with Shadow and asked for his assistance.

In the Hero scenario where Shadow agreed to help Sonic, the two destroyed the Black Tank. However, as they tried 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 the Black Arms were heading out to the Space Colony ARK, and decided to follow them. 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 invited him to come with him. Shadow accepted Sonic's offer and the two of them took off.

Sky Troops
In the Hero scenario of Sky Troops, Sonic had learned 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 invited him to come with him to the ARK. Shadow accepted Sonic's offer and the two of them took off.

As Sonic and Shadow approached the ARK in their spacecraft, the Black Arms' forces were waiting for them. Excited about the challenge, Sonic hurried out to engaged the enemies with Shadow.

Space Gadget
When Sonic and Shadow made it to 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, Sonic and Shadow caught a glimpse of the Black Comet. When Shadow asked what it was, Sonic realized that Shadow suspected 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 followed the Black Arms. As the two make their way through the ARK, Sonic and Shadow caught a glimpse of the Black Comet. When Shadow asked what it was, Sonic realized that Shadow suspected 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 hunting for Black Doom. After obtaining another Chaos Emerald, Sonic and Shadow finally found Black Doom and defeated him. As Shadow took the final Chaos Emerald from Black Doom, Sonic stood by Shadow's side, as Shadow pronounced 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 Commander in the Diablon, and teamed up with him to stop Shadow. When they found Shadow, Sonic was confused why Shadow sided with the Black Arms, but was amused to hear he did so just to get the opportunity to prove his superiority him. However, Sonic and the G.U.N. Commander were utterly defeated, and Shadow took the final Chaos Emerald from them. Sonic then commended Shadow for his nerve to do this, before Shadow announced he was now the most powerful hedgehog in the world.

Black Comet
In the Dark scenario of Black Comet, as Shadow was decimating G.U.N.'s forces on behalf of the Black Arms, Sonic teamed up with the Commander in the Diablon to stop Shadow. When they found Shadow, Sonic refused to let him do this, but he and the Commander were utterly defeated by Shadow, who took the final Chaos Emerald from them. As Sonic questioned Shadow why he sided with the Black Arms, Shadow proclaimed himself as the servant of Black Doom.

GUN Fortress
In the Dark scenario of GUN Fortress, as Shadow ravaged through the GUN Fortress on behalf of the Black Arms, Sonic teamed up with the Commander in the Diablon to stop Shadow. When they found Shadow, Sonic refused to let him do this, but he and the Commander were utterly defeated by Shadow, who took the final Chaos Emerald from them. As Sonic asked Shadow what he planned to do with the Emeralds, Shadow claimed he would 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. Black Doom however, took the Emeralds and used an enhanced Chaos Control to transport the Black Comet to the surface, intending to use humans as energy sources for the Black Arms. Before Sonic could act, he and the others were paralyzed by a nerve gas and Black Doom unleashed the Death leeches on them. Shadow however, was immune to the gas and as he left to stop Black Doom, Sonic told him that he was their only hope left.

Sonic and the others eventually escaped the Black Comet and found some shelter from where they cheered Super Shadow on as he defeated Devil Doom. He then witnessed Super Shadow sending the Black Comet back into space and destroying it with the Eclipse Cannon. Impressed by Shadow's victory, Sonic 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 stroll at Emerald Beach. As he examined it, Sonic displayed some fighting moves upon its request, forming a Link. 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. As Shadow told Sonic to keep the Gizoid from Eggman and left, Sonic presented Tails with the Gizoid, but then saw Rouge on the beach and left to investigate her. Rouge told Sonic she and the government were after the Gizoid too, but Sonic got her to leave after fighting 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 got there, however, Knuckles mistook Emerl for an E-121 Phi and attacked him. After Emerl beat Knuckles, Sonic and Tails explained everything and got Knuckles' Chaos Emerald which they gave to Emerl.

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

From there, Sonic continued Emerl's training until he saw Amy coming and ran away, only to learn when he returned that Rouge had stolen Emerl. Sonic later found Emerl with Rouge and engaged her in battle with Tails and Knuckles' aid and eventually made Rouge surrendered Emerl. Later on, Sonic left Emerl with Tails for a while and when he returned, he heard from Emerl 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 his parenting, he ran off when Emerl made a bad choice of words. He later returned and was told by Amy that he had to marry her now since she had helped raising Emerl, but Sonic fled 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 informed 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, and Sonic chose Emerl to be the one stop Eggman since the transporter could only send one at the time.

When Emerl left for the Death Egg, Sonic and his friends watched Emerl through a monitor on the Death Egg. After Emerl defeated Eggman however, the doctor fired the Final Egg Blaster, destroying some stars, which caused Emerl to revert to his original programming. However, Eggman was unable to control Emerl as expected, and Emerl prepared to fire the Final Egg Blaster at Earth. As The Master Emerald then appeared, Sonic went to the Death Egg with it, hoping to neutralize Emerl's power, but Emerl smashed the Master Emerald. Tails then told Sonic that he could stop Emerl by damaging him, but it would destroy him. With a heavy heart, Sonic engaged Emerl in battle and defeated him with his full strength.

As Emerl began to say farewell, Sonic, in a rare chase of emotional denial, tried to assure Emerl everything would be fine, only for Emerl to disappear. Back home, Sonic tried to comfort his friends over Emerl’s death and was positive they would see Emerl again one day.

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 had happened. Excited by this challenge, Sonic left with Tails to stop Eggman's newest scheme.

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 fighting Nega and searching for info, Sonic and Tails met Vanilla and learned from her that Cream was with Blaze. Once Vanilla told where to find them, Sonic took off to get answers from Blaze.

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. As Knuckles smashed some rocks in fury, Sonic and Tails continued through the path he had cleared. Soon after, they found Blaze and Cream, and Sonic asked Blaze about Eggman Nega, but Blaze noted she would deal with Eggman Nega and the crisis alone. Sonic tried to tell her they should work together, but Blaze declined and left with Cream, forcing Sonic and Tails to follow them. Along the way, Sonic and Tails ran into Amy, who provided them with directions to where Blaze went when they asked (though Sonic was hesitant to ask since Amy thought he liked Blaze).

Eventually, Sonic tracked Blaze to Dead Line where they faced both Eggmans. While Sonic insisted on helping, Blaze refused and tried to force him to leave by fighting him, a fight Sonic tried to stop. As their fight ended in a draw, Sonic saw that Blaze was still willing to manage the crisis and he understood her rough past. Sonic then 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 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 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 gathered help, 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 the doctors left to prepare for the coming fight, Sonic encouraged Blaze as she despaired, and, with 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 shook 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 investigating an unknown energy reaction in the Tornado, but got caught in a storm and sucked into a hurricane. Washing ashore on Southern Island, Sonic and Tails met Marine the Raccoon and they decided to explore the surrounding islands in this unknown territory. The next day, Sonic and Tails found Marine accidentally destroying her SS Marine that she was building. The duo then helped Marine build a new vessel, with Sonic providing the Materials, 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 to his surprise Blaze the Cat attack Whisker. Though confused at Blaze's arrival, Sonic teamed up with her to fight the Ghost Kraken. After the fight, the pirates escaped with the Jeweled Scepter, an artifact hidden in Coral Cave which Blaze tried to protect. As Sonic wondered why Blaze was here and not in her own world, he and Tails realized they had been transported to Blaze's world during the storm. After explaining their story, Sonic suggested to Blaze they worked together to get the scepter back which posed a threat to their worlds and she accepted it.

From there, Sonic and the group 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, the group found the pirates’ hideout in some ancient ruins. Before heading 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 her run off crying.

At the pirates’ hideout, Sonic faced Whisker and Johnny alongside Blaze. Despite beating them, however, Whisker escaped and Sonic and his friends saw Marine arriving and going after the pirates, only to get caught by the Ghost Titan. Fortunately, Sonic came up with a plan to distract Whisker by letting Tails pretend the scepter was somewhere else 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 Dr. 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 to Deep Core, the villains tapped into the Power of the Stars with the scepter, but 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 Sonic could leave, Blaze suggested that the Sol Emeralds and the Chaos Emeralds were responsible for their reunion, which Sonic remarked that they could never know for sure, before he shook hands with Blaze once more. As Sonic and Tails were taking off, Marine arrived in her SS Super-Marine to say goodbye. Sonic and Tails then promised Marine they would see each other again and headed back to their own world.

Sonic Riders
In Sonic Riders, Team Sonic arrived at 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 Storm 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. Regardless, Sonic was excited to have found new competition.

The next day, Team Sonic saw Dr. Eggman 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 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.

When Sonic and his team got to the finals, Sonic vowed to a taunting Jet that he would not to lose. When Sonic was about to win the race, Wave detonated the bomb under Sonic’s Blue Star, causing him to lose to Jet, much to Sonic's anger. Sonic and the others the saw Jet claim and use the seven Chaos Emeralds in tandem with the Key to Babylon Garden to reveal Babylon Garden itself, with the intention of claiming its treasure. Eggman, however, stole the key so that he could take the treasure for himself, believing it to be technology that he could use to conquer the world. Calling his team, Sonic headed out to stop Eggman. Using the Tornado 2, Team Sonic arrived at Babylon Garden, where Sonic received the Blue Star II from Tails and went after Eggman on it. On the way however, he was pitted again Jet, who was after Eggman too, and Sonic raced against Jet to Eggman as a rematch.

Sonic eventually beat Jet and cornered Dr. Eggman, but stopped when Eggman showed he had 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, furious at him for endangering her, chased after him with her Piko Piko Hammer. No sooner, Sonic and the others heard a roar from inside Babylon Garden and went to check it out. There, they saw the Babylon Rogues had awoken the Babylon Guardian and were forced to fight it.

After beating the Babylon Guardian, Sonic, Jet and the rest found the Treasure of Babylon, which turned out 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 that he would be ready to race him again the next time they met before taking his leave with his friends.

Sonic Riders: Zero Gravity
In Sonic Riders: Zero Gravity, a few months after the EX World Grand Prix, Sonic was driving with Tails and Knuckles through Monopole, fumbling thoughtfully with a mysterious meteorite Tails had found the other night. On their way to Megalo Station, they were attacked by SCR-HD and some SCR-GP, a part of a currently global robot rampage who were after the meteorite. In the insuring chase, the group fell out from a 300-story high building, but Sonic was saved by the meteorite by using it to manipulate gravity.

As Sonic and his friends tried to hide from the robots, they met Amy who 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. As Jet demanded the meteorites, called the Ark of the Cosmos, and said he wanted to challenge Sonic to a race, Sonic was eager to accept it, but 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 has 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 they tried to figure where the mother computer could be, Amy remembered Storm mentioning Gigan Rocks, which held information about the Ark of the Cosmos, so Sonic and the others went there to find clues.

At Gigan Rocks, the group learned from the ruins that the Arks of the Cosmos were power units for 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 told them Eggman had stolen their Arks of the Cosmos. As they conclude that Eggman planned to use them to control all the world's robots for world domination, Sonic almost headed out, when Jet demanded a race for the Arks of the Cosmos and title of the fastest in the universe, which Sonic accepted.

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 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 signed up to compete in the second World Grand Prix hosted by Dr. Eggman for the sake of the competition rather than the prizes. As they were interviewed by Omochao, Sonic was ready to start racing, though he suspected that Eggman was up to something.

In their first race, Team Heroes faced Team Rose, who Sonic was openly disappointed about facing. During the challenges, Sonic was berated by Amy for not going easy, but Sonic insisted on competing seriously. Once Team Heroes had beaten Team Rose, Amy demanded a date with Sonic to make it up for this, but 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, though Sonic was not surprised about facing Jet in the finals. In the final face-off, Sonic and his team beat Team Babylon, seemingly securing their victory. However, when he heard Jet had mechanical troubles during the race, Sonic called for a rematch, intending to have a fair race. Sonic therefore faced Jet in a one-on-one and defeated him. As Team Heroes was commended as champions, Sonic told the viewers how incredible he felt before noticing Team Babylon had left. When Omochao tracked Team Babylon down, 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, Sonic and the other teams came to the awards ceremony to collect their prizes, but Eggman made them have a final race against his "ultimate Gear-Jockey robot", which made Sonic suspicious. After the race, Eggman 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 his plan was lame. In retaliation, Eggman challenged Sonic and the others to a race, but lost. Sonic then noticed E-10000B was acting funny before seeing Metal Sonic emerging from it and heard that Metal Sonic had stolen Eggman’s data and replaced it with fake. Sonic then noticed that Metal Sonic was challenging him to a race and despite being told that Metal Sonic could not be beaten, Sonic gladly accepted the challenge.

Eventually, Sonic was victorious in the race and forced Metal Sonic to run away. As Eggman cursed being tricked, Sonic mocked Eggman for ruining his own plan. As the World Grand Prix drew to a close and the other teams began to leave, Sonic insisted that they all 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 Elise, 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. However, 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 they found the Emerald. After Sonic and Shadow defeated it, they used their Chaos Emeralds to make a rift back to the present. Through it, Sonic, Tails and Knuckles got back to the present.

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 by using Chaos Control with two Chaos Emeralds to create a rift. Sonic promised Silver to change his future by saving Elise before heading into the rift. Arriving 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, reforming 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.

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 watched the festival happily, hinting that he still remembered this adventure.

Sonic Rivals
In Sonic Rivals, when Onyx Island appeared at sea, Sonic and Tails went to investigate 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 Eggman (Sonic however, does not realize this throughout the game). Sonic confronted the doctor, but Eggman Nega pulled out a card depicting Amy Rose and explained he had turned Amy into a card with a special camera. Sonic did not believe it at first, but as Tails stated his opinion on 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 she and Sonic 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 discovering more dropped pages on the Ifrit. There, 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 attacked 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 Rings however, Espio appeared and took them, but Sonic pursued him. Afterwards, Sonic found Eggman Nega again and fought his Egg Bull. Afterwards, 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.

The two eventually found the portal to the Ifrit's dimension, which was about to close and they headed inside to find Eggman Nega before it was too late. 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. Though Sonic was occasionally taken over by the Ifrit too, 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 saved 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 his 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 enjoying some chili dogs while waiting for Amy, having somehow been talked into going on a date with her. Suddenly, however, he 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 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 soon found Nimue, who told them that she would only reveal the scabbard's secrets to him if Sonic passed a test of true knighthood, and gave him three tasks to finish within three day. Confident, Sonic told 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 committing 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. When Sonic returned with the scabbard of Excalibur to Merlina, she revealed that she had used Sonic to 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 help, Sonic and the Knights of the Round Table tried to contain Merlina's influence with a magical barrier. Sonic then faced Merlina, now the Dark Queen, who told him the fate of the kingdom to make him understand her. 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 awakened the sacred swords' power, transforming him into Excalibur Sonic and Caliburn into Excalibur.

Together, Sonic and Caliburn defeated Merlina and Sonic convinced Merlina to let go of her sadness and live her life to the fullest. As the Knights of the Round Table thought about disbanding without king, Caliburn revealed that Sonic was the true King Arthur of this world, much to Sonic's surprise. Despite his new title, Sonic returned home, where he told his adventure to Amy, but she thought it was an excuse for forgetting their date, leaving Sonic to run away from 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 no need to be a hero anymore, Sonic went on a long vacation alone. Some time later, he got a call from Tails who said that the Chaos Emeralds had been stolen and Knuckles had been kidnapped by a group dubbed the "Marauders" so Sonic agreed to help find Knuckles. On his way to Tails, Sonic joined up with Amy and they beat one from the Marauders.

With help from G.U.N., Sonic and his friends located the Marauders' hideout where they found Knuckles. 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. Suspecting Eggman was working with Marauders, the group looked for the doctor. Eventually, the team located Eggman. However, the doctor claimed that he had been reformed and was against the Marauders as well, and was willing to help Sonic and the others fight the Marauders by leading them into Metropolis where 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, the team came across Shadow who Sonic fought and convinced to join them. Later, Sonic and the others met a Marauder, called Shade, who revealed 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 found a way around it. In Metropolis, Sonic, Knuckles and a part of the group went to Angel Island to secure the Master Emerald, while Tails and Eggman prepared a weapon against the Nocturnus Clan.

By hijacking an airship and with some help from Tails' team, Sonic and his group got to Angel Island where they met the Nocturnus Clan’s leader, Imperator Ix, who sought to rule the world. Ix unleashed his soldiers and overwhelmed them, but Sonic stood his ground until Tails and Eggman appeared and deployed their weapon, which dispatched the soldiers. Sonic and his team then fought Ix, but were unable to stop him 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. 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, having realized the evil nature of her leader.

Using the newly-built Blue Cyclone, Sonic and the group entered the Twilight Cage while Eggman stayed behind. Inside the Twilight Cage, Sonic and his team got five of the Chaos Emeralds back and gained the alliance of the alien races residing in there. When they prepared to invade Nocturne to find the last Emeralds, Sonic united the alien races under them, who then helped them infiltrate 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 in the possession of Charyb and Scylla.

On their way, Sonic and Tails helped Knuckles' group defeat Gizoid Centurions. Sonic and his group then found Charyb and beat him with the help of Knuckles and his team and reclaimed the Chaos Emerald. Once Knuckles got their Chaos Emerald as well, Sonic and his group headed to Ix’s throne room where they saw Knuckles standing by his duty despite Ix's persuasions and attacked him. After the fight, Sonic and his team stepped in and stalled Ix, while Knuckles got the Master Emerald back.

After the fight, Ix 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 got through it just in time. When they returned home however, they realized that a lot of time had passed which allowed 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 where he fought a small army of Egg Fighters and Eggman in a powerful mech. During the battle, Sonic turned into Super Sonic, destroying Eggman's mech and his fleet. When he corned Eggman on a space station however, Super Sonic was lured into a trap and caught in an energy field where he had the Chaos Emeralds painfully ripped from him, returning him to normal. With the Emeralds' power, Eggman fired an energy blast at the planet, breaking it apart and awakening an ancient creature called Dark Gaia to harness its power. In the process, a part of Dark Gaia's energy infected Sonic and turned him into a "Werehog". Sonic was then rejected from the station and fell towards the planet with the powerless Chaos Emeralds.

Moments before impacting the ground, Sonic's fall was temporarily broken by a green light. After recovering from the fall, Sonic met an unconscious imp-like creature and awoke him. As they introduced themselves, however, Sonic realized that the creature had complete amnesia. Believing that he caused his memory loss by falling on him, Sonic promised to help him recover his memories. Dawn then broke and Sonic surprisingly returned to normal.

The duo soon arrived at Apotos where Sonic named 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, Sonic turned into the werehog again at night, and he realized the nature of this transformation. They soon ran into Tails who Sonic saved from Dark Gaia's Minions. As Tails recognized Sonic, Sonic explained his story to Tails and Tails took them to Professor Pickle, who could know something about this global crisis, in Spagonia with the Tornado-1. When they arrived, however, they learned Eggman had kidnapped the professor.

Sonic, Tails and Chip tracked Professor Pickle to Mazuri where they freed him from his prison in Eggman's base and reclaimed the stolen Gaia Manuscripts. After that, they learned from Pickle that Dark Gaia was behind the planet's shattering, but that it was not fully reborn. 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 soon after returned to Mazuri, where they saved the local villagers from Eggman and drove him off before locating a Gaia Temple. Inside the temple, with Chip's ability to activate it, Sonic was able to restore the Emerald and a continent, and soon after heard their progress from Tails' reports. When returning to Spagonia at night, Sonic met Amy, but when Amy did not recognized him as a werehog, Sonic became depressed about his different appearance. He later found Amy caught in a group of people possessed by Dark Gaia, but with Chip's help, Sonic exorcised the people and saved Amy. However, he left before Amy could see him, but eventually faced her with his condition.

Sonic and Chip continued their adventure across the world, healing it one piece at a time. At the sixth temple, however, Sonic noticed Chip was acting scared. As the two of them restored the sixth continent, Sonic saw Chip regaining his memories inside the sixth temple. Chip then revealed to Sonic that his 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 believed that Chip was the reason he remained the same as a Werehog, but Chip revealed that it was Sonic's own strong heart that prevented him from succumbing to the darkness. 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 Chip and convinced him to let him help him.

Sonic and Chip later arrived at Eggmanland to find the last temple. As they placed the final Emerald in the temple and the last continent was moving back into place, Sonic (in his Werehog form) and Chip believed it was over, but were then suddenly attacked by Eggman in his Egg Dragoon. After Sonic defeated Eggman at the planet's core, Dark Gaia itself appeared and knocked Eggman into the distance, before engaging Sonic and Chip. In the shuffle, Dark Gaia drew the last fragment of its power out of Sonic to complete itself, curing Sonic of his Werehog condition, but also weakening him. However, Sonic was saved when Chip called the Gaia Temples to him and formed the Gaia Colossus and the two of them fought Dark Gaia.

During the fight however, Dark Gaia matured and became Perfect Dark Gaia and began casting the world into darkness. Sonic, however, harnessed the Chaos Emeralds and became Super Sonic. Together with Chip, they defeated and sealed Dark Gaia, but Super Sonic was given a tough fight and he fell unconscious in his normal form. He was then returned to the surface by Chip, who got sealed inside the planet and returned to dormancy. Back on the surface, Sonic found Chip's necklace, which he kept as a bracelet. As he heard Chip's final goodbye, Sonic paid his respects to his friend and headed out for new adventures with 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, having survived their last encounter, returned to defeat Sonic with a new and improved army of Badniks. Sonic then began chasing and fighting Dr. Eggman while collecting Chaos Emeralds through the various Zones.

At the end of his journey, Sonic gave a final chase to Dr. Eggman, but Eggman retreated to the E.G.G. Station Zone, a base in space. Sonic, however, jumped onto a rising rocket and pursued the doctor. 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 in a rebuilt Death Egg Robot. Despite the mech's improvements, however, Sonic defeated it and escaped the base as it began exploding, before landing in Splash Hill where his adventure ended for the time being.

Episode II
In Sonic the Hedgehog 4: Episode II, after having defeated Dr. Eggman onboard the E.G.G. Station Zone, Sonic spent the next few months relaxing from his adventures. When Sonic heard that Dr. Eggman had returned and was up to no good on the neighboring continent, however, he prepared to stop Eggman and sought out Tails. The two of them then headed out together in the Tornado to investigate Eggman's newest scheme.

Arriving in Sylvania Castle Zone, Sonic and Tails began investigating. They eventually found Eggman and learned the doctor planned to turn Little Planet, which had made its annual return, into a power source for his Death Egg mk.II. As such, Sonic and Tails began chasing the doctor to stop him. Along the way, they were attacked by Metal Sonic, who had returned more powerful than ever to settle the score with Sonic under the alliance of Eggman, but Sonic and Tails defeated him in each encounter.

When they got to the Sky Fortress Zone, Sonic and Tails used an escape pod to follow Eggman and Metal Sonic to the Death Egg mk.II as the flying fortress was exploding around them. Onboard, they briefly fought Dr. Eggman and Metal Sonic until the villains escaped. Soon after, Sonic was challenge to a rematch by Metal Sonic, but he and Tails beat him again. Sonic and Tails went on and faced Dr. Eggman and his Egg Heart and defeated him, making the Death Egg mk.II crash. The two of them then used some escape pods to return home while watching the Death Egg mk.II shut down and be pulled away by Little Planet's orbit.

Sonic Colors
In Sonic Colors, Sonic traveled to Dr. Eggman's Incredible Interstellar Amusement Park, an amusement park made of planets, before its opening day with Tails as he was suspicious of Eggman's claim to have made it to make up for his past misdeeds. There, Sonic saved two Wisps from Orbot and Cubot, where the Cyan Wisp gave him his first Color Power. Meeting with Tails, who was building a translator to understand the White Wisp Sonic saved, Sonic reported to Tails what happened before going to discover Eggman's plan. Once he found Eggman, however, Sonic was attacked by the Rotatatron which he destroyed and unintentionally sent one of its pieces into one of the nearby towers. Returning to Tails, who had the translator ready, Sonic learned from the white Wisp, named Yacker, that Eggman was catching the Wisp, and set out to save them upon Yacker's request.

While exploring one of the amusement park's planets, Sonic found a generator which he subsequently destroyed and afterward learning from Tails and Yacker that Eggman was harvesting the Wisps' Hyper-go-on. While exploring the next planet, Sonic was saved by Tails from Eggman's Mind Control Ray, though the fox was temporarily mind-controlled. Eggman then send the local giant robot at them, but Sonic destroyed it and the local generator. Knowing now that Eggman was preparing a mind-control weapon with the Wisps' Hyper-go-on, Sonic discovered that Eggman used the generators to keep the Wisps' planets captive while he kidnapped the Wisps. Sonic then set out to destroy the remaining three generators, thinking this would stop Eggman's plans.

Traveling across Eggman's amusement park, Sonic successfully located and destroyed all the generators while at the same time freeing the captive Wisps. With the planets and the Wisps safe, Sonic and Tails returned to the Tropical Resort where they started celebrating with the freed Wisps. However, when the amusement park began to collapse due to Eggman's mind control cannon backfiring when the doctor tried to use it (which was because of the Rotatatron's piece that was unintentionally struck in it by Sonic), Sonic and Tails escaped to Eggman's space elevator to get back home. There, however, Eggman showed up in the Nega-Wisp Armor to crush Sonic. Wanting Tails to be safe, Sonic pushed him into the elevator and launched Tails back home, while he fought Eggman alone.

Though Sonic managed to defeat Eggman, he was still caught in the black hole created from the collapse of Eggman's mind control cannon. However, he was saved by the Wisps who got him back to Earth where he reunited with Tails and later saw the Wisps stop the black hole. Yacker then appeared and thanked Sonic and Tails for their help, but told them that he had to return to his own planet. Sonic then said goodbye to Yacker and watched the Wisps leave with the kidnapped planets.

Sonic Generations
In Sonic Generations, Sonic's history was interfered with by a mysterious foe called the Time Eater, which Sonic's past self, Classic Sonic, bore witness to.

In the present day, some time after Sonic Colors, Sonic's present self, Modern Sonic, arrived to see that his friends were holding a surprise birthday party for him which he delightedly joined. During the party, the Time Eater appeared and sucked Sonic's friends into different periods of Sonic's past. Sonic, unable to defeat it, was knocked out during the encounter and later awoke in the White Space. After passing through Green Hill, Sonic was able to restore Tails and the area from a colorless frozen state. Modern Sonic then decided to save his friends caught in the White Space with the same procedure, unaware that Classic Sonic was doing the same thing. When Modern and Classic Sonic passed through a Boss Gate, however, they came across each other, where Classic Sonic went ahead and fought Dr. Eggman when the doctor appeared, only to see him get caught by the Time Eater. After that, the Sonics discovered with the help of Modern and Classic Tails that they were traveling through time and space.

Teaming up to stop the Time Eater, the Sonics progressed through the White Space, restoring the frozen areas and their friends. Along the way, they learned from the Tails' that the Time Eater's actions ripped space apart, that their speed was the key to restoring space and time and finally, the Chaos Emeralds were the Time Eater's weakness, which they set their sights on collecting. When Modern Sonic later defeated Dr. Eggman in his Egg Dragoon, he and his friends witnessed Eggman getting caught the Time Eater again, much to their confusion.

The Sonics eventually obtained all the Chaos Emeralds and freed their friends before facing the Time Eater in its own domain. There, Dr. Eggman and his past self, Classic Eggman, revealed themselves as the ones behind the Time Eater in an attempt to erase Sonic from history so that the doctors would be victorious in the present. The two Sonics squared off against the Time Eater, but got knocked out. While passed out, however, the Sonics got support from all of their friends, allowing the Chaos Emeralds to activate and them both to transform into Super Sonic. Together, they defeated the Time Eater and stopped the doctors' plan. As a result, time was restored and the Sonics returned back to the present with their friends where Modern Sonic's birthday party left off. During the party, Modern Sonic thanked Classic Sonic for his help before saying goodbye to him and promising him a great future when Classic Sonic and Classic Tails returned to their own time.

Sonic Lost World
In Sonic Lost World, Sonic and Tails were chasing after Dr. Eggman, Orbot and Cubot in the Tornado to free some animals they had captured. As Sonic and Tails went after the captured animals in the Capsule Eggman dropped from the sky, the Tornado was damaged by Eggman's laser. As they fell from the sky, Sonic and Tails came across the Lost Hex. Landing on there, Sonic found the lost capsule and reported back to Amy and Knuckles. Soon after, Sonic found Dr. Eggman with the Deadly Six, a group of Zeti Eggman controlled. As Eggman left Zazz to finish him, Sonic fought and defeated Zazz, before reuniting with Tails. The duo then left to find Eggman.

After Sonic met and fought Zomom, he and Tails found Eggman scolding the Deadly Six. Despite Tails' warnings, Sonic recklessly knocked away the conch Eggman used to control the Deadly Six. However, this allowed the Deadly Six to rebel against Eggman by talking control of his Badniks and using them to attack everyone. When Tails got injured, Sonic escaped with Eggman, Orbot and Cubot to bring Tails to safety.

Escaping to Tropical Coast, Sonic and Tails parted with Eggman and his lackeys to deal with the Zeti. Meanwhile, they were contacted by Amy, who informed them that something was draining the world of life. After Sonic had encountered and faced Master Zik, he and Tails met Eggman again, who revealed that the Deadly Six were using his Extractor to destroy the Earth, which Sonic saw matched Amy's report. Reluctantly, Sonic teamed up with Eggman to bring him to the Extractor and have him shut it down properly.

While traveling, Sonic realized that Tails was mad at him for trusting Eggman more than him to stop the Extractor. While Sonic encountered and fought Zeena, he and the group were briefly contacted by Zavok, who stated the futility of their actions. Later, Sonic argued with Eggman on how to beat the Zeti when Tails got attacked by Cubot when he him on a Crabmeat, but Eggman saved him. Though perplexed by Eggman's behavior, Sonic scolded Tails. Later on, Sonic found and tried to open a lone capsule, but Tails stopped him, having seen it was a trap set by the Deadly Six, though Tails was caught in it and taken away, leaving Sonic ridden with guilt. Soon after, he found Zor and demanded him to return Tails, but Zor fled.

Later, Sonic came across Zavok and heard he planned to turn Tails into a robot. After fruitlessly chasing after Zavok, Sonic lost contact with Amy over the Miles Electric as her life dwindled away. Zavok then appeared and taunted Sonic with the loss of his friends, making Sonic fight and beat Zavok.

When Sonic and Eggman got to Lava Mountain, they were attacked by Zazz and Zomom, who made them nearly fall into a lava pit. Sonic, however, was saved by Eggman, who threw him back on ground while Eggman fell into the lava pit. After escaping, Sonic defeated Zazz, Zomom and Master Zik for good, though he was disheartened to have seemingly lost all his friends at this point. When he met Zavok, Zeena and Zor, Sonic was shocked to see that Tails had seemingly become a robot. When Tails was ordered to kill Sonic, however, Tails revealed 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.

With the Zeti taken care off, Sonic and Tails got to the Extractor only to discover that it was already turned off. Eggman then showed up in a new mech, having faked his death earlier so he could charge his mech while Sonic fought the Deadly Six and now planned to conquer the remains of the world. After Sonic beat Eggman, he apologized to Tails for doubting him, mending their friendship. When Eggman then tried to escape with a jet pack, Sonic revealed he removed its exhaust pipe, making Eggman fall down from the Lost Hex. After returning the world's energy, Sonic and Tails returned to Knuckles and Amy, where Sonic decided to take a nap to rest from his adventure.

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
"The fastest hedgehog in the world, this little blue speed demon often gets going so fast, he appears to be just a whirling blur. He'll usually be found in front of any of the speed-based events in these Olympic Games, and will be very difficult to catch in any of the short-distance sprints."

- Sonic's profile from the game's official website.

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
"Sonic the Hedgehog is a blue hedgehog that moves at Sonic speed who joins Mario as they go head-to-head at the Olympic Winter Games! Armed with his signature attitude and Spin Dash ability on the Wii and DS, and Jump Dash ability on the DS, Sonic brings a new level of competition to the Olympic Winter Games as his team goes for gold in Vancouver!"

- Sonic's profile from the game's official website

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 makes 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 and Wii U
Sonic was confirmed for Super Smash Bros. for Nintendo 3DS and 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.

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 and lives his life according to his own rules rather than the standards of those around him and without concern for what others think, and enjoys nothing more than traveling the world. Endowed with a strong passion for life, he is always moving forward to look for his next challenge, making his life a never-ending series of adventures. Because of his need for freedom, Sonic loathes the idea of being constrained, such as in Sonic Adventure 2 where he could not stand being held up in a tiny cell.

Sonic is most of the time easy-going, cool and care-free. However, he is often impatient, hates boredom and has a short temper. Because of his impulsive nature, Sonic can be reckless and quick to act before thinking, throwing himself into trouble without a second thought and regardless of other's warnings. Regardless, he is honest and always keeps his promises.

Sonic's personality is a juxtaposition of kindness and ferocity. He is extremely benevolent, driven by his own strong sense of justice and fair play, and firmly stands for freedom, but he is never the one to rest in the face of injustice or oppression. He hates all evil, exploding with anger when witnessing it, and will do all he can to snuff it out, throwing his life on the line without hesitation. However, he usually sees his heroics as an opportunity to have fun, making him a thrill-seeker. In times of crisis though, he is aggressive and focuses intensely on the task at hand as if his personality has undergone an astonishing change. At the same time, Sonic has a big and gentle heart and is fully committed to help out and protect those in all kinds of trouble at any time, even if his actions will have ill consequences.

Sonic has a lot of self-confidence and possesses a large ego to match it, making him sassy, quick-witted, cocky and sometimes overconfident. Possessing a narcissistic tongue, he often jokes around to light the mood, but will also take any opportunity to taunt his opponents. Despite this, he can be quite the gentleman when he wants to and be modest with fancy titles. Following his free-spirited nature, Sonic never dwells on the past or allows his loses or hurtful experiences to weight him down. Instead, he chooses to live in the present and always looks forward to his next adventure, while holding no regrets for whatever has transpired. Also, Sonic is incredibly strong of character and will: no matter the situation, he never doubts himself and will never give up no matter what. It is only in the moments of greatest loss that his macho and carefree appearance falls away.

Sonic is extremely loyal to his friends and will risk his life for them without any due consideration. While he can leave them hanging or even endanger them due to his fast-paced nature, and at times acts rude, Sonic never has any intention of making his friends unhappy and values them above all else. 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.

Regardless of the countless foes he has faced, Sonic rarely considers them true enemies, and instead tends to admire 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 outward demeanor, Sonic has shown to be much more insightful than he usually lets on, capable of seeing things others would have overlooked and can as well give valuable and comforting advice that drastically changes the outlook of others, such as Elise, Merlina and Blaze. 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.

Sonic has a fondness of the beauty of nature and he stands as a protector of it. He appreciates scenic views in Sonic Colors and showed 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 which is reflected in his Trick Actions. 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's greatest strength is his running speed, with the ability to instantly accelerate to and run at speeds exceeding that of Mach 1, which is at the blistering speed of 761 mph (1,225 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: Director's Cut 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 is even noted to be the fastest being in the universe. Additionally, he 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. 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. This suggests that Sonic can move at speeds far greater than the speed of light. Sonic's 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, showing he has complete mastery over his speed. 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 running, Sonic can also apply his super speed for other abilities. He is able to heal himself by vibrating his body at supersonic speeds, launch shockwaves by spinning in his spinball form at high speeds and create barriers of super speed for a split second. Sonic can also set strong winds in motions with high-speed movements which he can use to attack opponents similar to aerokinesis.

Physical abilities
Sonic has shown astounding feats of kineticism, precision and has reaction time to match his speed. He possesses incredible acrobatic skills and agility, alongside astonishing reflexes, making him able to avoid sizably voluminous and minuscule obstacles with precise jumps and delicate movements despite their incoming speed, 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 to jump up to several hundred meters, even when carrying extra weight.

In terms of physical prowess, Sonic has often been noted for lacking overall physical strength by comparison. Nevertheless, Sonic has demonstrated a small degree of superhuman strength (though nothing in comparison to Knuckles' strength). He is able to push things several times bigger and heavier than himself, carry beings as large as himself while still run at top speed, 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 latters power comes from his super speed, his super strength, or a combination of both. Most of Sonic's fighting moves involve his feet and legs more than his hands, which suggests that Sonic's legs are more powerful than his arms; as seen in Sonic Adventure 2, he was able to topple the colossal Egg Golem with a single kick. This does not mean that Sonic's arms are not strong either as demonstrated in Sonic the Hedgehog CD where Sonic exhibited enough strength to tear robots apart by hands.

At several times, Sonic has demonstrated 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 or 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 entry 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 out gunned, 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 abilities 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 defeat of Ultimate Emerl, who had the abilities of every character and all seven Chaos Emeralds (therefore being mainly superior to him in almost every way possible), is a prime example of this. 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 more on his speed and other abilities in his arsenal.

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; in the different versions of Sonic Generations, Sonic was able to beat the Egg Emperor and Perfect Chaos on his own where he previously required additional support and power.

Fighting style
In battle, 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. In hand-to-hand combat, Sonic makes use of his greater speed to deliver fast strikes to his opponents, allowing him to either deliver several strikes in a split second or strike foes with increased force. For stronger physical strikes, he tends to perform Spin Attacks, Spin Dashes and Homing Attacks.

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 just picked up a sword, Sonic was able to slay a dragon with swordplay and after receiving formal training from Caliburn, Sonic becomes capable of going up against and defeating several members of the Knights of the Round Table and King Arthur himself. By applying his speed to his swordplay, Sonic can make quick and swift slashes and as well become a buzzsaw with his sword by spinning. 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 the Hedgehog 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 which increases his speed further, where he envelopes himself in blue aura and turn himself into a projectile, allowing him to destroys any enemy caught in his path. He does not even need to have contact with the ground in order to execute the move and can use it to temporarily fly immense distances through midair.

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 spinball 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 also sense danger, before being attacked by a dinosaur.

Sonic has proven himself as a world-class Extreme Gear rider. On an Extreme Gear, he can move even faster than he can run and go head-to-head with the best Extreme Gear riders the world has to offer, namely Jet the Hawk. Sonic seemingly 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. Easily his most frequent transformation, Super Sonic is Sonic's ultimate form. In this state, all of Sonic's abilities far surpasses his normal ones and he is as well able to fly and is nearly invulnerable. However, this transformation consumes a lot of energy and requires Rings to be maintained.

Hyper Sonic
In Sonic the Hedgehog 3 & Knuckles, by using the power of the seven Super Emeralds, Sonic can achieve an extended and more powerful form of Super Sonic, called Hyper Sonic. This form basically shares the same abilities and traits as Super Sonic, except they are all more powerful and upgraded.

Darkspine Sonic
In Sonic and the Secret Rings, by harnessing the World Rings of rage, hatred, and sadness, Sonic can become Darkspine Sonic, a 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 pyrokinetic abilities. Because of the intense emotions sealed inside the World Rings that Sonic uses to transform, however, he 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. However, these transformations require a steady supply of 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 (Sonic has been stated to believe that if he falls in water, he will be trapped and no one would be able to get him out), though he does not demonstrate that fear very often. A slight exception being in Super Smash Bros. Brawl where he is able swim very briefly before drowning (although it is more of flopping around like a fish rather than actually swimming). 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 has also stated that if Sonic does not sleep for eight hours during the night, it would spoil his running.

Relationships
During his adventures, Sonic has encountered many people and throughout it all, 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 arch-enemy is Dr. Eggman, but Sonic has come across even greater enemies throughout his adventures.

Doctor Eggman
Dr. Eggman is Sonic's eternal arch-enemy and nemesis, who he ironically has known longer than anyone else. Along with Tails, Eggman is one of the figures who has often shaped Sonic's destiny. Because of Sonic's hatred of anything unjust, he holds a great mutual hatred for the doctor and his evil plans to take over the world, and he has spent years rescuing the victims of Eggman's conniving schemes. Whenever Eggman is cooking up a plan to conquer the world, Sonic always shows up and thwarts him. Because they always fight each other to win, Eggman has become a long time rival of Sonic's as well as an enemy. Also, whenever Sonic's anger explodes over injustice, he always makes Eggman the receiving end of this aggression.

Despite his dislike of Eggman, Sonic has never really taken account of his adversary and does not consider him his enemy in the true sense of the word. Whenever dealing with Eggman, Sonic remains fully confident that he can spoil his plans and never really takes them seriously. In fact, Sonic finds entertainment in spoiling Eggman's plans, which he sees as a way of making his life an adventure, and he is so used to beating him that he considers it an everyday job. Usually, Sonic is rather frank or taunting towards Eggman and will almost always seize the opportunity to tease him with jokes and sarcasm. Sometimes, Sonic even finds Eggman more bothersome and annoying than threatening: when he discovered Eggman was behind the Time Eater in Sonic Generations, Sonic just face-palmed and shrugged disapproving. Nevertheless, he remains vigilant about Eggman and his actions, like when he alone refused to believe that Eggman had turned over a new leaf in Sonic Colors. In the cases Sonic does deem Eggman a legitimate threat though, he becomes very serious about the doctor and targets him with fierce anger.

When presented with a more terrible threat that endangers both of them and their goals, Sonic is willing to put aside his differences with Eggman and join forces with him to stop it. Even in such cases though, Sonic remains reluctant about it, feeling that teaming up with Eggman is like the end of the world and a dirty affair, and will in some cases suspect the doctor has an ulterior motive (which is often proven true). Because of Eggman's complicated tendency to instantly switch between morals, Sonic has a hard time figuring out the doctor.

While Sonic has been know to make fun of Eggman by using his alias instead of his real name (which was possibly given by Sonic), he actually uses this name affectionately, rather than trying to make fun of him.

In spite of Eggman's horrible deeds, Sonic is content with just stopping the doctor and is never out to put him out of commission for good on purpose. Because of Eggman's tendency to survive their encounters and refusal to give up however, the doctor always returns with a new scheme, prompting Sonic to stop him again. As such, Sonic remains forever locked in a conflict with Eggman where it is nearly impossible for both individuals to defeat the other once and for all, making their battle a never ending one.

Miles "Tails" Prower
Miles "Tails" Prower is Sonic's best friend and sidekick, as well as his most faithful and loyal friend. Besides Eggman, Tails is one of the figures in Sonic's life who has often shaped his destiny. Sonic first met Tails on West Side Island where he noticed Tails was following him, but was not interested and ignored him. However, when he noticed that the fox cub kept following him and could keep up with his speed, Sonic grew impressed with his tenacity and ability to keep up, and decided to let him tag along. When Dr. Robotnik soon after attacked West Side Island, Sonic joined up with Tails when the fox followed him into the conflict. Over their adventure, Tails proved himself a great assistance to Sonic and after defeating Robotnik, the two had built the foundation for the unbreakable friendship that would define their future. Sonic eventually took Tails under his wing as his sidekick and began taking him with him on his adventures and training with him, eventually becoming his protégé. Additionally, Sonic would come to Tails' aid by stopping the bullies who would tease him for his twin-tails, which only improved Tails' admiration of him.

Since becoming friends, Sonic and Tails have been inseparable, their friendship having grown to the point where they have a brotherly relationship. In Sonic Advance 3, they are even noted to have an "Unbreakable Bond," and when Tails was mind-controlled into fighting Sonic in Sonic Colors, Sonic never laid a finger on him, refusing to hurt his friend. Sonic himself sees Tails as a cute "adopted" kid brother and looks over him accordingly. Nevertheless, Sonic respects and trust Tails immensely and treats him as his equal partner in their adventures. Whenever on an adventure, Sonic always asks Tails to come along and will always accept his help. At times, however, Sonic will ignore Tails when he gives advice or information, often when it's most useful, though he is not too big to admit he should had listened to him.

Sonic cares very much about Tails' well-being, even threatening those endangering him, and will always make Tails' safety his top priority above all else when he needs it, even if it means abandoning a fight, forcing Tails to leave for his safety, or make saving the world his secondary objective. Whenever Tails doubts himself, Sonic is always there to give him moral support. Throughout their adventures, Tails has continuously proven himself as Sonic's most reliable ally, always providing him with invaluable help, knowledge, and machines. In turn, Sonic is impressed with and appreciates Tails' work and considers his technical skills better than any other's, though this faith makes him leave all the tech work to him.

In Sonic Lost World, Sonic unintentionally strained his friendship with Tails when he planned for Eggman to do the necessary tech work to save the world, which made Tails mad at Sonic for trusting Eggman more. It was further strained when Tails endangered himself when using a battle bot to help and Sonic scolded him. At the end though, Sonic apologized for doubting Tails and Tails forgave him, mending their brotherly bond.

Amy Rose
Amy Rose is one of Sonic's oldest and most loyal friends, and his self-appointed girlfriend. Since before and after meeting Sonic, Amy has looked up to him as her hero and been madly in love with him, and her greatest wish is to marry him. Sonic first met Amy during his adventures on Little Planet where he saved her from Metal Sonic and Dr. Robotnik's captivity which made them fast friends. Right from the start though, Sonic has not liked her like a girlfriend or reciprocate her advances, though it has done nothing to deter Amy.

Since their first meeting, Amy has chased Sonic down wherever he goes, with Sonic seemingly unable to escape her, and has tried to win his heart by any means. Sonic, however, is rather annoyed by her affection and even disturbed by her over-the-top displays, which makes him treat Amy as little more than an annoyance and deem her weird. As such, Sonic considers Amy a near constant pain in his life. Whenever Amy tries to show him affection, Sonic gets rather uncomfortable, exasperated or embarrassed, and will try to avoid her when she goes overboard, usually by running away or by more rude means. He also refuses the idea of marrying Amy, preferring to be locked up (which is no small statement considering Sonic's loathing of being constrained) as seen in Sonic Adventure 2. Additionally, Sonic is scared of Amy's anger which makes him nervous or run away in fear when he thinks he will provoke her, and he often finds himself overwhelmed by her powerful personality. Over the course of the series, Sonic running away from Amy has become a frequent gag.

Regardless of how much dismay Amy has put Sonic through, she is considered one of his best friends. It is stated that in his heart he may not dislike her as much as it seems, and that deep down he might actually have some feelings for her. In Sonic Unleashed, Sonic was stumped that Amy did not recognize him as the Werehog, and when he shortly after saved her from some of Dark Gaia's Minions, he initially chose to run away than face her with his condition. Additionally in Sonic Lost World, Sonic was crestfallen when he thought Amy and the others had died from the Extractor.

Overall, Sonic cares about as Amy a good friend and worthy comrade whom he can rely on and he appreciates her efforts to help him when she is not flirting with him. Also, whenever Amy is in trouble, Sonic will always be there to help her out should the need arise, though he tends to overlook her when she is caught in the middle of his showdowns with the villains.

Metal Sonic
Metal Sonic is Sonic's robotic alter ego, created by Dr. Eggman for the sole purpose of destroying him. He is one of Sonic's earliest foes and his first true rival, being able to copy both his speed and power, and they have a violent rivalry/enemy relationship. Sonic first encountered Metal Sonic on Little Planet where the robot kidnapped Amy Rose, forcing Sonic to defeat him to save Amy, inadvertently turning Metal Sonic from one viewing him as an enemy into a bitter and deadly rival. On the other hand, Sonic has never considered Metal Sonic his enemy in the true sense of the word.

Since meeting each other, Sonic and Metal Sonic have almost always fought whenever they meet, never once having an instance where their objectives align. In Sonic's opinion, Metal Sonic is the worst creation Dr. Eggman has ever made, due to how it always causes trouble for him, and he views him as a very serious threat. Regardless, Sonic always remains confident that he can beat Metal Sonic and considers him a "lame robot copy" which can never match up to the original that is him, though it does not keep him from enjoying testing his skills against him.

Over time, Sonic and Metal Sonic have had countless fights. While Metal Sonic is one of Sonic's few rivals who have come the closest to defeating him, Sonic has always beaten him in the end. However, these defeats only served to increase Metal Sonic's hatred for Sonic and endowed him with an obsession to surpass and defeat him, promoting him to repeatedly challenge him in vain. In Sonic Heroes, Metal Sonic's hatred and obsession for Sonic pushed him over the brink, making him usurp control of the Eggman Empire to build a robot kingdom with the goal of killing Sonic. He even adopted the warped belief that Sonic was his copy and that he was the real Sonic. In the end, Sonic still defeated him, and while Metal Sonic refused to give up after that, Sonic promised his robot double that he would await their future rematches.

Knuckles the Echidna
Knuckles the Echidna is one of Sonic's best friends and a friendly rival. They have known each other for a long time, but their relationship is somewhat complicated. Sonic first met Knuckles in Sonic the Hedgehog 3 where they started off as enemies, with Knuckles trying to keep him from stopping the Death Egg's re-launch. However, when they discovered that Dr. Robotnik had tricked Knuckles, the two of them joined forces to keep Robotnik and his robots from stealing the Master Emerald, and they departed on good terms.

Sonic and Knuckles are much like oil and water. While Sonic exemplifies the wind, laid-back, cool and free, Knuckles is the mountain, stern, serious and unmovable. Because of their differences and morals, they do not understand each other and they do not always see eye to eye. They share a competitive rivalry and they often end up fighting when clashing, though their rivalry has become more friendly over time. With Sonic's speed equaling Knuckles' strength in every way, their fights are always climactic, though at times unsettled, which only provokes them to clash further.

Knuckles sees himself as Sonic's rival, though it is implied it is because he envies Sonic's free lifestyle and self-reliant nature. Sonic meanwhile, always welcomes a challenge from Knuckles and enjoys teasing him for fun because of his serious nature, and will even try getting him angry so he can fight him. Whenever Sonic discovers Eggman has tricked Knuckles, he always chides him by calling him "Knuckle-head," though he always makes peace with him at the end of the day.

Despite their differences, Knuckles is Sonic's best friend next to Tails, and according to Tails, they are "funny" together. While not holding back on his shortcomings, Sonic acknowledges Knuckles' skills and knows he can count on him to do what is needed to succeed. Over time, their relationship has improved and they argue less, though Sonic is somewhat reluctant to admit when Knuckles is right and he was wrong. While Knuckles at times rebuts his help and claims he could do better, Sonic just rolls with it and is merely glad to help him. The two are also great and loyal team-mates, having been called "Fighting Buddies" in Sonic Advance 3, and when they work together they form an unstoppable team. For better or worse, Sonic will also be there to give Knuckles needed, if not harsh, consoling whenever he is in doubt. Additionally, in Sonic Lost World, Sonic was crestfallen when he thought Knuckles and the others had died from the Extractor.

Shadow the Hedgehog
Shadow the Hedgehog is Sonic's arch-rival. They look almost identical (to the extent that many got them confused in Sonic Adventure 2), and they can match each other in speed, agility and abilities, including Chaos Control. The two of them first met each other as enemies, with Sonic holding a grudge at Shadow for getting him into trouble with GUN, but they put aside their differences to team up and save the world from Gerald Robotnik's doomsday plans. Since then, they have been both lethal enemies and comrades.

Shadow is the antithesis to all that Sonic stands for, and ever since they first met they have fought, argued, and even sometimes had outright death matches, though Sonic is never out to take Shadow's life and does not consider his rival an enemy in the true sense of the word. Their moral differences are as far apart as black and white, always causing the two of them to clash. Sonic has a joyful, free-spirited attitude that looks for fun adventures, while Shadow is a brooding loner with a merciless and excessively violent edge. Sonic has few limitations on his goals and will do anything to help save the world, but Shadow will stop at nothing to get what he wants without any concern of who or what it affects. Nevertheless, they do not care of each other's views and they always see their conflicting differences as yet another reason to fight each other.

Both Sonic and Shadow initially shared a bitter arch-rivalry. When they first met, Sonic accused Shadow of copying him, with Shadow maintaining a mutual belief regarding Sonic. This feeling is still present in both of them because each believes he is better than the other. Regardless, their rivalry has developed over time and is now more friendly.

Out of all his rivals, Shadow is the one whom Sonic struggles most with. As shown in all the clashes between them, they are nearly equally strong or as strong as the other, with both sides 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, which has only increased the intensity of their arch-rivalry. They have an unshakable need to showcase their growth and improvement for every encounter they have, and anything considered competitive is suitable for their rivalry, though Sonic usually remains more casual about it than Shadow and rather enjoys testing his skills against him.

Despite their differences, Sonic and Shadow share a mutual respect between them, though this is rarely apparent because they always argue and fight. During their adventures, Sonic has acknowledged Shadow's power and capabilities, even admitting that Shadow is only one who would have a chance against him in a race, and after Shadow sacrificed himself to save the world in Sonic Adventure 2, he recognized him as a brave and heroic hedgehog. Sonic also appears to hold faith in Shadow's sense of right and wrong to small extent, as seen in some of the scenarios of Shadow the Hedgehog where he would show disbelief and confusion about Shadow siding with the Black Arms, and even admitted in one scenario that he did not believe Shadow had it in him for his selfish acts. Regardless of their objectives, they are willing to put their differences aside for the greater good if they must, and together they are an unbeatable team. Overall, there is always extreme tension between Sonic and Shadow, but they have matured over time, with Sonic having become more acceptant of Shadow's violent tendencies.

Blaze the Cat
Blaze the Cat is one of Sonic's friends and most valuable allies. He first met Blaze in Sonic Rush where he initially suspected she was involved with Dr. Eggman Nega's current world-conquering scheme. When he found Blaze, Sonic learned she was not an enemy but was actually working on saving the world, though she wanted to bear that responsibility alone. Sonic insisted they should help each other, but Blaze refused. Regardless, Sonic followed Blaze into a showdown with Eggman and Eggman Nega where he would not let her fight alone. However, Blaze still refused his help and fought him to make him leave.

As they fought, Sonic tried to stop Blaze, but she berated him with the full fury of her emotions. After their battle, Sonic understood she had a rough past and he told her not to handle too much alone and be true to herself. This advice made Blaze realize that accepting help would benefit her, and they properly introduced themselves and became friends. Later, when Blaze lost faith in herself when the Sol Emeralds lost their power, Sonic showed up and cheered her up which let her become Burning Blaze, and they defeated Eggman and Eggman Nega together. After the battle, they said goodbye, where Blaze thanked Sonic and they promised to meet again.

Following their first adventure, Sonic and Blaze have steadily become better friends and trusty allies. The two have a custom that when they have to depart after an adventure, they shake hands, signifying their growing friendship and respect following their encounter and the promise that they will meet once more.

Sonic and Blaze are alike in many ways, having similar skills and duties, yet very different backstories and contrasting personalities: Sonic being inwardly free and adventurous, yet outwardly level-headed and cool, whereas Blaze is outwardly stoic and blunt, yet inwardly highly emotional. However, their differences does little to hurt their relationship and is later shown to mix very well in Sonic Rush Adventure as their friendship and mutual understanding grows. They are also shown to be great partners in combat and they work well together, almost as in synch.

Sonic and Blaze share a great deal of mutral respect and trust. Like Blaze respects Sonic and his skills, Sonic has acknowledged Blaze's skills after she matched him in direct combat and he willingly entrusted her to bring Cream back safely shortly after befriending her while she trusted him to face Eggman Nega. Also, whenever Blaze's emotions get the better of her, Sonic shows concern for her and calms her down, like when he told her to remember her duty to her people when she was taking a risk to fight for the Jeweled Scepter. Additionally, Sonic is responsible for many changes in Blaze's outlook on life. Their time together enabled Blaze to discover the meaning of friendship which ultimately let her use the Sol Emeralds, and his advices made Blaze accept her pyrokinetic powers as a gift rather than a curse.

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 since they met, and their relationship is based on their competitive nature and their distinct respect for one another. When meeting with each other for the first time, Sonic was beaten by Jet when facing him on an Extreme Gear. However, Sonic was left rather impressed by Jet's skills and instantly recognized him as a new rival.

During Eggman's first EX World Grand Prix, Sonic was not exactly fond of Jet as he constantly taunted and insulted his attempts at mastering Extreme Gear, often getting very angry at him. While thinking Jet was rather full of himself, Sonic still recognized his 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 keep a professional, yet competitive, attitude around Jet. Eventually, Sonic settled his own dispute with Jet when he beat him in a race. 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 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.

The Deadly Six
The Deadly Six, a gang of villainous Zeti initially controlled by Dr. Eggman, are some of the most hated enemies Sonic has ever faced with Zavok being the worst, not only because they threaten the safety of the world, but also due to the role Sonic had in their uprising and that he had a personal score to settle with them. When Sonic first met the Deadly Six, he treated them with confident mockery like he would with any other villain he met. When Sonic later recklessly got rid of the Cacophonic Conch Eggman used to control the Deadly Six however, they rebelled and planned to destroy the world, making Sonic responsible for their uprising and the subsequent danger to the planet. As such, Sonic set out to stop them more seriousness. Meanwhile, the Deadly Six saw Sonic as a growing threat and sought to turn him into a robot so his power could serve them.

When the Deadly Six captured Tails instead of him, Sonic, having lost his cool for once, became extremely hostile towards them in his quest to rescue Tails, threatening them with aggressiveness and spite which only intensified as Zavok taunted him with his plans to turn Tails into a robot and his friends' apparent deaths. When they met in Lava Mountain, Sonic moaned of how tired he was of them and threatened them with violence when he thought they turned Tails a robot. In the end though, Sonic defeated the Deadly Six and got Tails back, redeeming his actions his involvement with the Deadly Six had brought, and proving himself the hero he is.

Friends/allies

 * Miles "Tails" Prower (best friend and sidekick, close as brothers)
 * Knuckles the Echidna (best friend and rival)
 * Amy Rose (self-proclaimed girlfriend)
 * The Chaotix
 * 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
 * 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
 * Caliburn
 * Merlina
 * Shade the Echidna
 * Chip (good friend)
 * Yacker
 * Wisps
 * Classic Sonic (past self)
 * Classic Tails

Rivals

 * Shadow the Hedgehog (arch-rival)
 * Knuckles the Echidna (old rival)
 * Silver the Hedgehog (friendly rival)
 * Jet the Hawk (rival in speed)
 * Metal Sonic
 * Johnny

Enemies

 * Dr. Eggman (arch-enemy)
 * Orbot
 * Cubot
 * Metal Sonic (robotic doppelgänger)
 * Eggman Nega
 * Fang the Sniper
 * Imperator Ix
 * Chaos (former)
 * Biolizard
 * Iblis (Sonic the Hedgehog (2006) only)
 * Solaris (Sonic the Hedgehog (2006) only)
 * Ifrit
 * Dark Gaia
 * King Arthur
 * Erazor Djinn
 * The Deadly Six
 * The Time Eater
 * Black Doom

Adventures of Sonic the Hedgehog
In Adventures of Sonic the Hedgehog, 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 in several comical adventures.

One day, Sonic came across a young orphan named Miles Prower and was persuaded to adopt him as his younger brother, as the young fox had none to live with. Naming him new brother "Tails", they two of them became as close as a real family. While Sonic has his trademark attitude, 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 together, 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. During his early childhood, however, his adopted family was captured and roboticized. He then joined his Uncle Chuck and the Freedom Fighters in the battle against Robotnik over the next many years. One day however, Sonic was approached by the Oracle who revealed to him 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
In Sonic the Hedgehog: The Movie, Sonic lives on Planet Freedom and is one of the defenders of the Land of the Sky, alongside Tails, who protects it from the evil Dr. Robotnik and his forces. He lives with Tails on their own private island.

One day, Sonic and Tails were called by Dr. 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 succeeded with his plan, Sonic worked together with his friends and allies to stop his metallic copy from destroying the world.

Sonic X
In the anime series Sonic X and its comic series published by Archie Comics, Sonic originally lived on a parallel version of earth in another dimension. During one of his battles with Dr. Eggman, 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. In 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 continuously attempted to conquer earth. 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, Chris, who did not want him to leave, ran off with him, 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 went home, and Sonic himself went back to his normal battles with Dr. Eggman.

Sonic Boom
In the Sonic Boom franchise, Sonic is the leader of Team Sonic, a group of heroes who protects Bygone Island and the earth at large from Dr. Eggman and his legion of robots. Though initially kind of a loner, the many trials Sonic faced during his battles against Lyric taught him the importance of teamwork, and he has since grown into a capable and admirable team-mate and leader.

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 (2005—2009) and Sonic Universe (2009–present) are based on the settings established by earlier animated TV series, the Sonic the Hedgehog 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 Nikki. Nikki transforms into Sonic whenever he wishes he had the strength to overcome a dangerous or stressful situation, but nobody (even Nikki) is aware of this transformation.

Nikki's girlfriend Eimi also has a crush on Sonic, and Nikki's father Poly, a pilot, claims that Sonic once saved his life long before Nikki 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 the gratest and most famous hero on his world. Sonic was born during the Great War to Jules and Bernadette Hedgehog and was originally named after his grandfathers (he later legally changed his named to "Sonic" with no offense to his forebears). While very young, he lost his parents to the first clandestine roboticization experiments. He was taken in by his uncle, Sir Charles Hedgehog, where he briefly played delivery boy for his uncle's chilidog stand while spending time in Knothole. Aside from his abnormal speed, Sonic was an average child.

Tragedy struck when Uncle Chuck was captured Dr. Ivo Robotnik and his forces following the doctor's takeover and roboticizied. Sonic and a few others were herded to Knothole by the Original Freedom Fighters who gave Sonic the inspiration that would make him a hero. From there, Sonic threw his full support behind the Knothole Freedom Fighters and fought to liberate the kingdom. Sonic playfully took on Dr. Robotnik's first few generations of badniks, growing in skill until, by his mid-teens, he was a true threat to Robotnik's forces and became a beacon of hope for the world.

As Sonic developed his incredible speed, his attitude became legendary. Irreverent, confident, impatient and energetic, Sonic fought constantly and eventually succeeded in overthrowing Dr. Robotnik, and continues the fight against his successor, Dr. Eggman. During his adventures, he has traveled the globe, and even traversed outer space, alternate dimensions, and time itself. He has been named the chosen hero of the multiverse, having throughout his endeavors faced down mad scientists, evil wizards, warmongering aliens and even gods. Following Operation: Clean Sweep though, Sonic met several loses that lead to the disbandment of the Freedom Fighters, making him assume leadership of Team Fighters to continue the fight. 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 was forever altered 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.

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. 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. Notably, Sonic recently made a number of cameo appearances 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, "Escape from the City" 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.
 * 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.
 * In Sonic Adventure 2, Sonic Riders, Sonic Riders: Zero Gravity, Sonic Free Riders and Sonic Unleashed (while in Werehog form), 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.
 * 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 cels, 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.
 * Apparently, Sonic and his friends are able to breathe in space (as seen in several games), 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.
 * 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.
 * Sonic likes to whistle as shown in several games. However, he whistles more in the Japanese versions of the games.
 * In Sega's other game 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 Hatsune Miku -Project DIVA- Extend to also celebrate his 20th anniversary.
 * 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.
 * Sonic appears to be able to juggle as was shown in Sonic Unleashed when Sonic was juggling the drained Chaos Emeralds.
 * Sonic is the inspiration for the Character Gears from the Anime Aoi Sekai no Chuushin de, which is coincidently a reimagining of the 'Console Wars' between Sega and Nintendo, with many other parodies of popular Sega and Nintendo characters appearing alongside Gears.