Sonic the Hedgehog

Sonic the Hedgehog is the most important member of the Knothole Freedom Fighters, under the reputation of "the Hero of Mobius". In another timeline, he was a cartoon hero. According to Bowser Jr. and Metallix the Metal Sonic, he also is the future king of Mobius, though he denies it.

Appearance
Sonic is an anthropomorphic hedgehog with a round head and an equally round torso. He has blue fur that covers most of his body, peach skin that covers his arms, muzzle and torso, and black eyes. He has six quills on his head, two spines protruding from his back and a short tail.

Before the Super Genesis Wave
Although Bowser Jr. believes Sonic's history is identical to the one of his cartoon counterpart, his history is actually identical to the one of his counterpart from a comic book belonging to Wendy O. Koopa.

Past
Not much is known about Sonic's past, but at some point he met Princess Sally and Bowser Jr. and quickly befriended them. His relationship with Sally, however, seemed to be somewhat beyond friendship. This was hinted by Bowser Jr. at a ball, where Sally only wanted to dance with him, as Bowser Jr. called Sonic "Sally's knight in shining armor". Bowser Jr. saw their relationship as love at first sight.

As the Hero of Mobius
When Dr. Eggman took over shortly afterwards, Sonic and Sally hid in Knothole, along some common friends of theirs (Rotor Walrus and Antoine D'Coolette). The four of them started an organization known as "The Freedom Fighters". Since Sonic did most of the work, he got the reputation of "The Hero of Mobius".

At some point, he met up with a two tailed fox named Miles Prower. Sonic decided to adopt him as his brother and started to call him "Tails", which the fox really enjoyed.

He had a confrontation with a giant dinosaur robot named Universalamander. He tried to destroy it, but failed and was turned into his demonic Super Form, Fleetway Sonic. He was calmed down by Sally, who also turned on into her Super Form.

Personality
Sonic is overall a fun and fast daredevil out on an ego trip. Having saved the world numerous times has left Sonic with an inflated sense of self as he thinks highly of himself. Throughout his life, Sonic has exhibited a great desire for adventure and excitement, in keeping with his super speed. Thrill-seeking aside, he genuinely cares for the people and things he fights for, which at times has led him to break the rules in order to do what he thinks must be done. His greatest flaw in this area may be that he has developed something of a need for action, which leaves him uneasy in times of peace and often influences his decisions more heavily than any other factor. Though he has great loyalty to his friends, family, nation, and Mobius in general, he has shown a tendency to be hesitant about committing to anything that doesn't allow him to fight for the things he cares about.

He has a bragging nature and that shows as he enjoys gloating about his accomplishments even going so far to rub others noses in it. Even though he isn't intrigued by the marital proposals at all he enjoys all the attention he gets from females sometimes. Depending on the person Sonic can either treat them great and be happy to give them his time or outright ignore them. Sonic is also clever and intelligent.

In dealing with his enemies, Sonic is usually light-hearted in behavior, often mocking his opponents with insults and puns. Given how serious he can be in some cases, however, it is likely that these jokes are an attempt to lighten the mood or project an air of confidence. Of course, it also serves (in most cases) to aggravate his enemies to the point of distraction. A milder form of this behavior is found in ribbing of his various friends and allies, who he often attempts to get them to loosen up.

Sonic enjoys being laid back and confident, rarely showing any signs of being put off by anything. It is only in the moments of greatest loss that his macho and carefree appearance falls away.

Deeply devoted to his friends and family, Sonic enjoys helping them every chance he gets. In particular, he helps less confident individuals express themselves and toughen up, as when he helped Mina Mongoose use her singing talents. However, he also has something of a bullheaded streak which causes him to think that he is right and everyone else is wrong. This had led him to clash with other such strong personalities as Sally. Sonic is clever and prefers to make up plans as he goes along, whilst Sally is more tactically minded.

For all his rough edges, Sonic has shown himself to be quite a gentleman, almost always showing respect to women. While he tends to treat her differently, Sonic also shows Sally a great deal of respect.

Powers and abilities
Sonic's most notable ability is his super speed, allowing him to run at speeds far surpassing Mach 1 which is at the blistering speed of 768 mph or more. His speed allows him to perform impressive feats, such as vibrating at high speeds to such a degree that it allows him to pass through solid objects and heal himself. More amazing feats of Sonic's speed is his ability to ball up water, and throw it, all in less than a millisecond. Such feats have even included him being able to scoop up dirt, toss it in the air and walk on it like a bridge. It is possible that he can access greater levels of speed.

Sonic has also been known to innovate various techniques to increase speed and acceleration. His most popular instance of such is the Spin Dash, a technique in which he assumes a ball or wheel like shape by tucking his arms, knees and head to his core, and rotates on the spot at blurring speeds and takes off at the speed of rotation at the time of release.

When using 7 Chaos Emeralds, Sonic can transform into Super Sonic, a nearly omnipotent golden hedgehog. If he's stressed, however, he can transform into Fleetway Sonic, a demon causing nothing but destruction. The only one able to calm down Fleetway Sonic is Super Sally, turning Fleetway Sonic into Super Sonic.

Sally Acorn
Sonic is shown to have a great fondness for Sally, not to mention the fact he secretly has a crush for her. As such, he would often find in desperation if he can't argue directly to Sally on plans, an example being when Eggman fooled Sally into going to Robotropolis, occasion when Sonic couldn't calm down until Bowser Jr. prematurely deployed Metallix. He often claims that Sally is the rightful queen of Mobius.

Bowser Jr.
Sonic and Bowser Jr. are good friends. Bowser Jr. is the only one who seems to know about Sonic's crush for Sally, as he calls Sonic "Sally's knight in shining armor". Bowser Jr. would sometimes mock Sonic into telling him that he should be the king of Mobius. Nevertheless, they still are good friends.

Metallix the Metal Sonic
Sonic often sees Metallix as being overprotective with him, as he can take care of himself. Metallix suspects that Sonic and Sally are into an "opposite gender attraction".

Miles "Tails" Prower
Tails is Sonic's adopted brother, sidekick and best friend. Learning that Miles Prower hated his true name, he started to call him "Tails", since Miles had two tails.

Dr. Eggman
Dr. Eggman is Sonic's archnemesis. The main goal of the Freedom Fighters is to defeat Eggman for good. Sonic would often mock Eggman in battle, as he is always confident he will win.

Trivia

 * According to the creator of the fanfiction "Freedom Fighters NEO", The Merger Magikoopa, Sonic was going to become far more serious, moodier, distrusting, and unforgiving after "The Endgame Saga", which focuses on the events of Archie's "Sonic the Hedgehog"- Issues 47-50, as he would become unable to afford not to care about Sally anymore.
 * This will have consequences such as trying to find a compromise to an ultimatum given by Sally in the infamous Issue 134 from the same comic series, in which, after Sonic chooses to be a hero instead of being with her, she forces a breakup, and the prevention of Sally's robotization in Issue 230 (from yet the same series).
 * Other characters would, however, warn Sally about her robotization.
 * Sonic will, however, try to maintain his cool, light-hearted demeanor.