Sonic the Hedgehog

"Sonic's the name, speed's my game!"

- One of Sonic's famous catchphrases

"Gotta go fast!"

- Another of Sonic's famous catchphrases

"Way past cool!"

- Another of Sonic's famous catchphrases

"You're too slow!"

- Sonic in Super Smash Bros Brawl

"Let's do it to it!"

- Another of Sonic's famous catchphrases

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

- Sonic the Hedgehog, Sonic Adventure 2

"Ready to roll champ?"

- Sonic in Sonic Adventure

Sonic the Hedgehog is the main protagonist of the popular video game series of the same name, all TV series of the same name, and all comic books of the same name, as well as Sega's mascot. Sonic's rival in the gaming industry used to be Mario, but now they are seen as friendly competitors ever since Sega became third party and started releasing their titles for Nintendo systems.

Sonic is a 15-year-old hedgehog known for his Super Sonic/Hyper Sonic speed (hence his name), and his laid-back and cocky attitude towards serious situations. His arch-nemesis is Dr. Eggman, but much like Mario and Bowser, Sonic always seems to the part his plans, no matter how hopeless or dire the situation may be. Sonic's best friend is Tails, who at times acts like a brother to Sonic and aids him in any way he can. Knuckles is his second best friend but also his first rival. Amy is his self proclaimed girlfriend.

Sonic has also had many voice actors throughout his history. In his first speaking role in Sonic's Schoolhouse, he was voiced by Meg Inglima. In the cartoons, he was voiced by Jaleel White; all the way though in Sonic Underground, his singing voice was provided by Samuel Vincent. From 1999 till 2004, he was voiced by Ryan Drummond. He was later replaced by Jason Griffith, who had previously voiced the character in the English dub of Sonic X and who also voiced Tom on Chaotic. Griffith kept the role until 2010, when he was replaced by Roger Craig Smith, who has voiced Sonic since then,he also voice Ezio Auditore da Firenze from the Assassin's Creed series. In the 2019 movie, he is voiced by Ben Schwartz, who also voices Skidmark in Turbo, Dewey Duck in Ducktales, Randy Cunningham in 9th Grade Ninja and Leonardo in 2018 reboot of Rise of the Teenage Mutant Ninja Turtles.

Although Sonic is the protagonist in all the games, in Shadow the Hedgehog: the videogame, Sonic is the deuteragonist.

Personality
Sonic is often shown as a character who wants nothing short of adventure. He absolutely enjoys adventure, and goes on one every chance he gets. If nothing interesting is going on, he flat-out bolts. He is always fun-loving and is always trying to make the best of things, and is always willing to help others. He is incredibly determined to do the greater good, and is always described as hating evil just as much.

He has an indomitable will, which was showcased multiples times throughout the series. He never holds grudges, and quickly forgives former enemies (an example being Knuckles the Echidna and Silver the Hedgehog), despite their initial encounter.

While he loves adventuring, Sonic has shown moments of relaxing (i.e. taking a nap or sitting down somewhere and enjoying the scenery). Sonic lives in the here and now, never dwelling on the past and just takes it in stride. He really cares about his friends, as he never lets them come to harms way (via saving Tails or Amy from Dr. Eggman's clutches).

In contrast to his cockiness, Sonic has shown to be modest when it comes to titles, telling Shahra that he was gonna blush (shown in  Sonic and the Secret Rings), or in Sonic Advance 2, where he becomes shocked by Cream the Rabbit calling him mister (and because of her politeness). Sonic has a high amount of charisma, since many people respect and look up to him.

His favorite food is chili dogs.

Physical Abilities
Despite not having undergone any known training, Sonic's years of battles has made him a skilled and powerful fighter. He has defeated giant robots, demons, and god-like beings on his own, gone up against and bested those with far more combat experience, and even beaten people who are his equal in abilities. It has also been noted that Sonic is steadily growing stronger during the Time Eater incident, Sonic could beat the Egg Emperor/Perfect Chaos on his own where he previously required additional power. Sonic even tells Infinite upon holding his own against the latter compared to the previous time they fought that he becomes more powerful every second. It is safe to say that Sonic is far more powerful than he lets on, but his overconfidence and reluctance to go all out usually keeps him from fighting at full strength. His victories over Emerl at the Gizoid's maximum potential and Perfect Chaos in his base form are prime examples of Sonic's true power. Regardless of his blocks, Sonic ranks amongst the most powerful characters in the series.

Super Speed: Sonic's greatest strength is his super speed, an innate talent that members of the hedgehog species possess. Sonic, however, has proven himself in a class of its own with his speed, having been credited as "The Fastest Thing Alive" and even the fastest being in the universe. He has the ability to instantly accelerate to the speed of sound and run at speeds far greater than Mach 1 which is at the blistering speed of about 768 mph, and can run backwards just as well as he can forwards. Due to such speed, he can scale vertical surfaces and ceilings, run over water, out speed lasers, and even cause the ground to explode in his wake. Even then, Sonic can take his speed even further. By revving up in one place, he can take off at turbo speeds in an instant. He can also envelope himself in a blue energy field that lets him accelerate beyond the sound barrier on both the ground and in midair for a short time, allowing him to not only smash straight through enemies and obstacles like a living projectile, but also fly immense distances through midair. Using certain techniques, he can even achieve light-speed momentarily.

It's unknown what Sonic's unaided top speed is. In Sonic Battle, it is stated that he can move several times the speed of sound and when facing Ultimate Emerl, he went at least ten rounds with him in less than thirty seconds. It has often been stated that Sonic can move at supersonic speed (which ranges from 915-3,840 mph), and he has once been called the "the world's fastest, hypersonic hedgehog" (which ranges from 3,840-7,680 mph). There are as well records stating that Sonic can move faster than the speed of light, although their accuracy cannot be guaranteed E-123 Omega himself calculated that Sonic's speed could potentially exceed light speed as Sonic confidently replied that light speed was "small time" to him.

Sonic has demonstrated complete mastery of his speed in any environment, and can use it for both high-speed offense and defense. Not only can he run at maximum tilt in straight lines, but also in full tight circles and through sharp turns with full control over his momentum. He can heal himself by vibrating his body, launch shock waves by spinning rapidly, leap in midair, launch stunning waves with fast punches and kicks, increase the force of his blows by striking with increased momentum, and create barriers of super speed. He can also spin in circles or rotate his extremities at super speed to create winds strong enough to attack or blow away opponents, similar to aerokinesis. Sonic possesses astounding kineticism, precision and has reaction time to match his speed. He has profound acrobatic skills and agility, along with enhanced reflexes that lets him avoid any incoming obstacles with precise and delicate movements. As seen in his first meeting with Silver, Sonic can even detect attacks beyond his field of vision due to his sharp reflexes.

Enhanced Stamina: As far as stamina goes, Sonic's is seemingly limitless as he is never winded from running.

When launched into the air, he can also pull off several tricks before landing. He also has incredible jumping skills, capable of jumping up to several hundred meters even with extra weight.

Enhanced Strength: Sonic possesses high physical strength, though he has been noted to lack overall raw power by comparison. He can push and lift things several times bigger and heavier than himself, run without extra weight slowing down and his attacks can smash through metal and rock, and damage foes countless times his size. However, it is debatable whether the latter's power comes from his speed, strength, or a combination of both. Sonic's strength particularly lies in his legs; with a single kick, he can topple the Egg Golem, knock back several Egg Gunners at once and send Badniks flying. This does not mean that Sonic's arms are not strong either; he has enough strength to tear robots apart by hands and punch through a collapsed wall

Enhanced Durability: Sonic has several times demonstrated extreme resilience to damage. He can survive getting caught in the crossfire from all angles by Eggman's robots (which only knocked him out cold briefly), withstand the force of a massive explosion and a Hyper-go-on-based black hole unscathed, being pummeled with swords, and smash through several robots with his fist without discomfort. Additionally, Sonic has more than once survived impacts from falls at extreme heights, bordering at the edge of space, only to shake it off when landing, and has even withstood atmospheric entry.

Indomitable Will: Sonic possesses an indomitable force of will; in situations where most others would give up and where he is severely outnumbered and outgunned, Sonic never loses faith in himself and never surrenders. This trait enables him to keep on fighting when utterly exhausted or after taking an abnormal amount of damage. His will even lets him withstand mind-controlling powers, like the corruptive influence of Dark Gaia and the Overmind's psychic powers, though he did have some protection in the latter case. Even when possessed by the Ifrit, Sonic was arguably able to occasionally regain control.

Chaos Powers: Sonic has also demonstrated the ability to harness chaos energy for his own use; with a Chaos Emeralds, Sonic can perform Chaos Powers, such as Chaos Control, and occasionally gain a boost in power.

Spin Attack, Spin Dash, Spin Jump and Homing Attack: Sonic's core offensive maneuver is the Spin Attack, a technique where he curls into a concussive ball or cutting disk and directs himself at his targets. With it, Sonic can shred or burrow through just about any substance given enough speed and hit with enough force to pierce colossal boulders. Highly adept in its usage, Sonic can utilize several variants of the Spin Attack for both ground- and aerial maneuvers, including the Spin Dash, Spin Jump, Homing Attack and the super-charged Focused Homing Attack.

Master Hand-to-Hand combatant: Even without his Spin Attack, Sonic is a highly skilled hand to hand combatant, and he has his own fighting style and is very skilled in it. He mostly relies on his fast footwork since the majority of his power lies in his legs, though he has been known to use his fists and arms as well, albeit in a rather straightforward manner. His fighting style is mostly derived from breakdancing moves which utilize Sonic's legs to their fullest, allowing him wide-ranged and swift kicks. He has also been known to use flying forward kicks, split kicks, and scissor kicks. What Sonic lacks in strength for combat, he makes up for it in speed which he use to deliver lightning fast strikes in a short time. His feats include defeating The Deadly Six, The Death Egg Robot, The Egg Dragon, Perfect Chaos, The Egg Emperor, Shadow the Hedgehog, Silver the Hedgehog, Knuckles the Echidna, Espio the Chameleon, Infinite, The Egg Cerberus, The Egg Genesis, and the Egg Wyvern.

Swordsmanship: Sonic is also shown to excel in swordsmanship. Even as a rookie swordsman, Sonic could beat a dragon, and after receiving formal training, he could best master swordsmen like the Knights of the Round Table. In addition to using advanced techniques, Sonic can apply his speed to his swordplay for quick and swift slashes, and become a buzz saw by spinning with his sword, enabling him to slice clean through enemies.

Extreme Gear Skills: Sonic has proven himself as a world-class Extreme Gear rider. He is said to move faster than he can run on an Extreme Gear and can go head-to-head with legendary Wind Masters like Jet the Hawk. Sonic seemingly has a knack for Extreme Gear riding, quickly grasping the controls on his first try and later developing advanced techniques despite being self-taught. After the second World Grand Prix, Sonic can be considered the best Extreme Gear rider in the world, having beat Metal Sonic in a race, who at that point was an "unbeatable" rider with the skills of the world's finest Extreme Gear riders at his disposal.

It appears that Sonic can control the strength and durability of his otherwise soft quills at will. While he is in spinball form, they appear to be extremely hard like buzzsaw blades; as demonstrated in Sonic Heroes, his quills (and body) are durable enough to slice through battleships without even moving at the speed of sound. In addition, Sonic's quills can sense nearby dangers, which they warn him about by creating a tingling sensation. Sonic has also demonstrated the ability to transfer his speed throughout various parts of his body, allowing him to immediately set off from stationary positions, and even channel it into objects to speed up their movements and make them pierce through solid objects as he does while running. He can also create an effect reminiscent of a time halt, although it is unknown what it is derived from.

Equipment
Though he does not prefer to use weapons (mainly dissing firearms), Sonic has wielded a number of tools during his adventures, albeit never permanently. During the Emerl incident, he utilized deployable landmines in battle, and one time, he would wield his own version of the Piko Piko Hammer. On his trip through the world of the Arabian Nights, Sonic also wore Shahra's Ring, allowing him to harness Shahra's magic for himself. Similarly, in the world of Camelot, Sonic would wield swords; he initially wielded Clarent, but later exchanged it for Caliburn, a sentient sacred sword with magical properties.

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 surpass his normal ones. He is also able to fly and is nearly invulnerable. However, this transformation consumes a lot of energy, meaning it cannot be maintained for long.

Hyper Sonic
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 traits as Super Sonic, except Hyper Sonic commands greater power and his Super State abilities are all upgraded. He also gains a new ability called Hyper Flash, which can destroy all foes in one flash. In addition, he's immune to drowning and can breathe underwater without a water shield.

Hyper Mode
A weaker variant of the super transformation. Sonic is capable of using this mode for a brief time on his own in Sonic the Fighters by drawing power from the Chaos Emeralds. In Hyper Mode, Sonic's speed and attack power greatly increase.

Darkspine Sonic
By harnessing the World Rings of rage, hatred, and sadness, Sonic can become Darkspine Sonic, a form powered by his emotions over Shahra's death. In this state, Sonic can fly, has greater strength, unlimited usage of his 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
By using the power of the four sacred swords, Sonic is able to transform into Excalibur Sonic. This form grants Sonic 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
After unwillingly absorbing the corruptive energies of Dark Gaia, Sonic gained the power to turn into a werewolf-like form named Sonic the Werehog at night time. In this state, Sonic loses his trademark speed, but he still retains his lightning reflexes and agility. He also gains super strength, sharp claws, extendable arms, and limited energy manipulation. While Sonic's strong will prevents him from going bonkers like most others would, he does gain some minor feral behavior. He permanently lost this form before his battle with Dark Gaia when the energy from Dark Gaia that granted him his Werehog form was re-absorbed by Dark Gaia to complete its full awakening into Perfect Dark Gaia.

Color Powers
By harnessing different variants of Hyper-go-on from Wisps, Sonic can use specific Color Powers to transform into a certain form, such as a drill, a laser or even a fireball, each one possessing its own unique abilities. So far, Sonic has been able to transform into 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 and 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 believes that if he falls into water, he will be trapped with no one to get him out), though he does not demonstrate that fear very often. A notable exception is in Sonic Free Riders, where he is able to effortlessly swim underwater in the Dolphin Resort, and in Mario &amp; Sonic at the Olympic Games and Mario &amp; Sonic at the London 2012 Olympic Games, Sonic is the only character to wear a life-preserver. In some games, Sonic can bypass his weakness to water by running or sliding across its surface, leap out of the water with successive jumps, and survive extended periods of time underwater with air bubbles.

It has been stated that if Sonic does not sleep for eight hours during the night, it would spoil his running. In addition, he has trouble keeping his balance when coming to an sudden halt when running at high speed.

Dr. Ivo "Eggman" Robotnik
Dr. Eggman is Sonic's eternal arch-enemy and nemesis, whom he 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 mutualismo hatred of 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 true sense of the world. 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, seeing as a way of making his life an adventure, and 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 Ester in Sonic Generations, Sonic just facepalmed and shrugged disapproving. Nevertheless, he remains vigilant about Eggman and his actions, like when he alone refused to believe 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 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 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 him out.

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

In spite of Eggman's horrible deeds, Sonic is content with just stopping the doctor and os never out to put him out of commission for good on purpose. Because of Eggman's tendency to survive their ecounters 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
Tails 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 following him. Though he was not interested in Tails at first, Sonic grew impressed with his tenacity when he kept up with him and let him tag along. When Dr. Eggman then attacked West Side Island, Sonic joined Tails when the Fox followed him into the conflict. In time, Tails proved himself a great ally to Ao nice, and after defeating Eggman, the two had built the foundation for the friendship that would define their future. Eventually, Sonic took Tails under his wing as his sidekick and took upon himself to train him. In time, the fox become his protector. Additionally, Sonic would stop bullies from teasing Tails for his twin-tails, which only improved Tails' admiration of him.

Since meeting each other, Sonic and Tails have been inseparable, their friendship having grown up 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 once mind-controlled into fighting Sonic, Sonic never laid a finger on him in refusal to hurt his friend. Sonic himself sees Tails as a cute "adopted" kid brother and looks him accordingly. Nevertheless, he respects and trusts Tails immensely and treats Jim as his equal partner in adventures. Whenever on an adventure, Sonic always asks Tails to come along and will accept his help at any time. That said, however, Sonic will ignore Tails when he gives advice or information, often when it is most useful, though he is big enough to admit he should had listened to him.

Sonic cares very much for Tails' well-being. He will not hesitate to threatened those who endanger him, and will always make his safety his top priority, regardless of the matters on hand, like when he sent Tails away against his will when the Nega-Wisp Armor attacked them. When Tails finds himself in doubt, Sonic is always there to give him moral support. Throughout their adventures, the two have proven themselves a perfect team who can handle nearly anything; both provide strengths to the other's weakness (Sonic handles the muscle while Tails handles the smarts) and neither of them would get far without the other's aid. Tails as in particular proven himself Sonic's most reliable ally, always providing him with invaluable help, knowledge, and machines. In turn, Sonic is impressed with Tails' work and considers his technical skills unparalleled, though this faith makes him leave all the tech work to him.

Sonic usually holds absolute faith in Tails' skills, although that faith has been known to waver. When Sonic planned for Eggman to do the tech work to save the world from the Deadly Six's abuse of the Extractor, his own frustrations over having caused the mess made him doubt Tails' skills. This would strain their friendship over time. At the end though, Sonic apologized for doubting Tails, mending their brotherly bond.

Amy Rose
Amy Rose is Sonic's best friend after Tails and Knuckles, as well his self-proclaimed girlfriend. Since before meeting Sonic, Amy has locked 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. However, this attitude has done nothing to deter Amy.

Since their fist 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 dêem her weird. As such, Sonic considers Amy a near constant pain in his life. Whenever Amy tries to shown 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. Rejecting the idea of marrying Amy, Sonic would rather be locked up in a cell than marrying her (which is no small statement considering Sonic's loathing of being constrained) as seen in Sonic Adventure 2. Additionally, Sonic fears Amy's angry; he will become nervous or run away when he thinks he has provoked her, and Sonic often finds himself overwhelmed by her powerful personality. Over the course of the series, Sonic running away from Amy has become a running gag.

Regardless of how much dismay Amy has put Sonic through, he consider her a great friend. 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 of her. In Sonic Unleashed, Sonic was strumped 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. Fortunately, learning that Sonic was inside the monster form, she claimed to him that he was still the Sonic she loves. 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 close friend and worthy comrade whom he can rarely 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 copy, created by Dr. Eggman for the sole purpose of destroying him. He is one of Sonic's earliest enemies and his first true rival, being able to copy both his speed and power. Both of them share a violent rivalry/enemy relationship with each other. 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 considered Metal Sonic his enemy in true sense of the world.

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 Metal Sonic as a very serious threat. Regardless, Sonic always remains confident than he can beat Metal Sonic and considers him a "lame robot copy" which can never match up to the original that is him. Still, this does not keep him from enjoying testing his skills against him.

Over time, Sonic and Metal Sonic have had countless fights, with Sonic always managing to beat or tie with Metal Sonic in the end, although not without cutting it close on most occasions. However, these defeats have only increased Metal Sonic's hatred for Sonic and endowed him with an obsession to surpass and defeat him, promoting him to repeatedly challenge Sonic in vain. At one point, 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.

While Sonic has managed to defeat Metal Sonic time and time again, he rarely condemns Metal Sonic for his villainous actions in the aftermath. Instead, he gets a satisfaction from the challenge Metal Sonic provided him with and will promise his robot double will that he will await their future rematches.

Knuckles the Echidna
Knuckles is Sonic's best friend after Tails. They have known each other for a long time, but their relationship is somewhat complicated, the two of them having been summed up once as "best frenemies". When Sonic first met Knuckles, 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, befriending each other.

Sonic and Knuckles are much like oil and water. While Sonic exemplifies the wind and is laid-back, cool and free, Knuckles exemplifies the mountain and is stern, serious and unmovable, which cause them to argue a lot. Because of their differences and morals, they don't understand each other and they don't 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, being now a more a play between the two. With Sonic's speed equaling Knuckles' strength in every way, their fights are always climactic.

Knuckles sees himself as Sonic's rival, though it has been implied several times it is because be 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.

A majority of their confrontations have been caused by Dr. Eggman, who would trick Knuckles into thinking Sonic (and to a minor extent, Tails) is the enemy; though, as time passed, Knuckles has stopped falling for Dr. Eggman's lies and is generally more aware of his plans. Whenever Sonic discovers Eggman has tricked Knuckles, he always chides him by calling him "Knuckle-head", which Knuckles does not take too well, though they always make peace of each other at the end of the day.

Despite their differences, both values more their friendship than their rivalry and both are willing to risk their lifes for each other. The two of them are connected by a hot-blooded friendship and according to Tails, they are "funny" together. While Sonic doesn't hold back on Knuckles' shortcomings, they deeply acknowledge each other and Sonic knows he can count on him to do what is needed to succeed. Over time, their relationship has improved greatly, though Sonic is still 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 teammates, having worked together multiple times, being called "Fighting Buddies" in Sonic Advance 3, and when they do so 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.

Cream the Rabbit
Cream the Rabbit is Sonic's close friend.

Blaze the Cat
Blaze the Cat is one of Sonic's friends and most valuable allies.

Silver the Hedgehog
Silver the Hedgehog is Sonic's friend and rival.

Chip
Chip is a dear and good friend to Sonic.

Jet the Hawk
Jet the Hawk is Sonic's rival.

Deadly Six
The Deadly Six are some of the worst enemies Sonic has ever faced.

Infinite
Infinite is Sonic's enemy.

Avatar
Avatar is Sonic's friend.

Quotes

 * "No way!"
 * "Long time, no see!"
 * "I'm Sonic. Sonic the Hedgehog."
 * "Whoa!"
 * "Yahoo!"
 * "Hey!"
 * "Man!"
 * "I'm outta here!" - Sonic CD
 * "Aw YEAH! This is happenin'!" - First words from Ryan Drummond.
 * "This sh/could be fun." - in Sonic Adventure and Sonic Forces.
 * "Hey, I'll play with you some other time." - after defeating a boss in Sonic Adventure.
 * "Something bugging you?" - when Knuckles makes his first attack against Sonic.
 * "Oh SHOOT! I've lost Amy! I bet that robot hauled butt after her! I better catch her before it does!" - Sonic getting lost in Twinkle Park.
 * "Uh... Okay... Whatever you say... You must have your reasons." - agreeing to leave E-102 Gamma alone for Amy because he helped her.
 * "What was that all about? I don't think I'm dreaming here." - after finding himself back to where he was.
 * "t won't change how he feels inside, will it? His heart will still remain in turmoil and his anger just won't vanish!" - claiming that sealing Chaos in the Master Emerald will not change anything
 * "Talk about low budget flight, no food or movies? I'm outta here! I like running better." - escaping from the Guardian Units of Nations, Sonic Adventure 2.
 * "Those robots are a total pain in the... WHAT?!" - Just before noticing Shadow above the defeated Big Foot.
 * "Now I know what's going on! The Military has mistaken ME for the likes of YOU! So! Where'd ya think YOU'RE going with that Emerald?! SAY SOMETHING... YOU FAKE HEDGEHOG!!!" - finding another hedgehog with the stolen chaos emerald.
 * "The reason I'm in here is because of that fake Hedgehog!" - explaining to Amy about what happened before he's arrested again.
 * "Whew. so far, so good. Hey, that's... (Shadow: That blue hedgehog again of all places..) I've found you, faker! (Shadow: Faker? I think you're the fake hedgehog around here. You're comparing yourself to me? HA! You're not even good enough to be my fake!) I'll make you eat those words!" - confronting Shadow in the first clash.
 * "BLOWS UP...?! (...) I've gotta get outta here and find Amy and Tails. RIGHT AWAY!" - after hearing from Eggman on radio.
 * "NOW, SHADOW!!!" - before he and shadow teleports the ARK back to where it was.
 * "Oh, It's noting. Come on, let's go home! To the planet as cool and blue as me! (...) Sayonara... Shadow... the Hedgehog." - Sonic in the end of Sonic Adventure 2.
 * "Time to crack that Eggman wide open! Yeah, let's party!" - in the beginning of Team Sonic's story of Sonic Heroes.
 * "Hmm, didn't you know? WE have a date with Eggman, too!" - to Team Dark that both teams have a date with Eggman.
 * "Hey! That's my line!" - confronting Team Dark.
 * "Okay, then. Let's get ready to do this. We'll show that creep the REAL SUPER POWER OF TEAMWORK!" - every team working together to confront Metal Sonic who copied every team's data.
 * "Alright!! Our next adventure awaits us, so there's no time to wast! YEAH! WE'RE SONIC HEROES!" - Ryan Drummond's last words.
 * "Looks like the party's getting started! Time to rock and roll!" - ready to fight the black arms, Shadow's own game.
 * "You need to be true to yourself." - to Blaze, Sonic Rush.
 * "I'll show you what true speed really is!" - Sonic Riders.
 * "Even with out wings, I can still fly! Right?" - after winning the final race with the Babylon Rogues.
 * "What, that lame robot copy of yours again? You really need to get a hold of better toys!" - When Eggman dispatches Metal Sonic for another race, Sonic Rivals.
 * "My... That's a pretty snazzy performance there." - when rescuing Elise for the first time, Sonic (2006).
 * "Just call me Sonic." - when Elise called her Mr. Sonic.
 * "Nothing starts until you take action. If you've got time to worry, then run!" - giving Elise an advice to go on by.
 * "Chaos Control!" - controlling time and space.
 * "And enough of that 'rat' stuff! Seriously! I'm a hedgehog! HEDGE-HOG!" - after Erazor Djinn calls him a rat, Sonic and the Secret Rings.
 * "If this is your world, then it's a world that I don't want any part of!" - confronting Erazor Djinn.
 * "Amy? What're you doing here?!" - stumbling upon Amy, Sonic Heroes and Sonic Riders: Zero Gravity
 * "Hey! Hold up a minute. Girls hate guys who rush them, Jet." - coming to Amy's aid after Jet accuses her for stealing the Arks of the Cosmos, Sonic Riders: Zero Gravity.
 * "C'mon! Step it up!" - Super Smash Bros. Brawl.
 * "Yeah, this is the real me. Pretty cool huh?" - to Chip, Sonic Unleashed.
 * "Yo, Eggman. Thanks for that little skydiving adventure the other day!" - meeting Eggman in Mazuri.
 * "A planet sized-jigsaw puzzle? Sounds like a great excuse to see the world." - after Tails' report.
 * "Guess I can't be the hero every time." - reply to Merlina meaning he's ready, Sonic and the Black Knight.
 * "But that's...!" - noticing Nimue looks like Amy.
 * "Heh, I'm the World's fastest Hedgehog. Check it out! You'll be calling me "Sir" Before ya know it!" - before leaving Nimue's lake.
 * "Some things never change..." - meeting Lancelot.
 * "Says you." - to Caliburn.
 * "Aw, man.. You sound just like that Knucklehead too." - after Gawain says Sonic's after a dragon's treasure.
 * "I'm Sonic. Sonic the Hedgehog. I have no master. Except the wind that blows free." - introducing himself to Blaze.
 * "It was never about chivalry for me. I just gotta do what I gotta do. THAT'S ALL!" - badly beaten by the Dark Queen.
 * "No, no! It's true, I tell ya! YIKES!!! NO, AMY WAIT! PUT DOWN THAT HAMMER!" - Jason Griffith's last words.
 * "Wait, we're going up against them? Seriously?!" - thinking Team Sonic's up against Team Rose again, Sonic Free Riders
 * "Because Eggman, plus Secretly built amusement park equals evil plot for us to foil. lucky for us, he's not very good at keeping things hidden." - response to Tails in the beginning of Sonic Colors.
 * "Yeah I'll just stick with aliens if that's okay with everybody." - breaking the fourth wall.
 * "Eggman! I AM going to save this planet, and I AM going to free these aliens. No copyright law in the universe is going to stop me!" - before fighting the Refreshinator.
 * "Look I know you're trying to be clever with this whole amusement park pun thing, but it's just coming off lame. Say you're going to destroy us and stop embarrassing yourself." - telling Eggman to give it a rest with his lame speeches.
 * "A hedgehog's gotta do what a Hedgehog's gotta do." to Tails in the end of Sonic Colors.
 * "Well, I can jog around the planet again if you want." - to Tails after knowing that about his surprise Birthday party, Sonic Generations.
 * "No stranger than rescuing genies in magic books or saving aliens in an Interstellar Amusement Park. I'm more concerned about finding our Friends." - to Tails finding themselves in White space.
 * "An adventure's no fun if it's too easy." - to Classic Tails.
 * "Hey Sonic! Enjoy your future. It's going to be great!" - Sonic's farewell to Classic Sonic.
 * "If you leave your game, stay safe, stay alert, and whatever you do, don't die. Because if you die outside your own game, you don't regenerate. Ever! Game Over!" - Sonic's PSA message in Wreck-It-Ralph!
 * "Okay, if it pleases the court, all those who think Eggman is a total bonehead, raise their hands." - as he sends Eggman away, Sonic Lost World.
 * "Oh no, what I meant to say is I'm so sorry that you have nothing more important to do in life?" - meeting Zeena the second time in Frozen Factory.
 * "I'm supposed to be the fastest, but I was too slow to save my buddy." - blaming himself for being too reckless after causing Tails to be captured by the Deadly Six.
 * "You know, after a daylight today, I can enjoy a nap on some fresh green grass." - in the end of Sonic Lost World
 * "Man, I can feel the sunshine. It's brightening up my day!" - LEGO Dimensions.
 * "Great! See, Infinite, now we're getting to know each other! So, what's your favorite color? Do you like long, romantic walks on the beach? What's the source of your power? You can skip the first two questions if you'd like." - His second encounter with Infinite.
 * "It's been generations since I've seen you. You okay?" - Sonic's reunion with Classic Sonic.
 * "Hey, don't be scared. This is your moment to shine! Keep going. Don't let your fear own you!" - cheering the Avatar up before he battles Infinite in Metropolis.
 * "I'm in a class all my own! Time to put-up or shut up, Infinite!" - before he battles Infinite in the Eggman Empire Fortress.
 * "Cheer up, Tails, I'm sure We'll run into him again." - after Classic Sonic returns to his own dimension.
 * "Hey, you taking off, too? I was thinking the same thing. Gonna keep moving forward, no matter what, yeah? Heh, you and I aren't so different. See ya later, buddy." - Sonic's farewell to the Avatar in the end of Sonic Forces.
 * "It's actually pronounced Wi-Fi, Ralph. (Wreck-It Ralph: Yeah, that's what I said.) And Wi-Fi is the Internet, which is an online community where human beings go to shop, play games and socialize. (Vanellope von Schweetz: Ooh, fun!)" - Sonic about the Internet in Ralph Breaks the Internet.

Trivia

 * One of the few things that can actually scare Sonic is an enraged Amy chasing him with her Piko Piko Hammer.
 * His Sonic Boom counterpart has blue arms (as opposed to flesh colored).
 * It's currently unknown as to the information of Sonic's family, as well as how he and Dr. Eggman became enemies.
 * Despite water being his biggest weakness in the vast majority of continuity's, he was perfectly able to swim in The Adventures of Sonic the Hedgehog.
 * Sonic Colors is the only canon game in which Sonic can swim. Although it is in the form of infinite jumps when underwater.
 * Sonic is highly notorious for breaking the 4th wall.
 * There is a genome named "Sonic hedgehog".
 * Every time Sonic appears in a band, he is either playing the guitar, or a Disc Jockey.
 * 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 Shakespearean language.
 * In 1993, Sonic was the first video game character to be seen in the Thanksgiving Day Parade.
 * In 2011, a second balloon based off of Sonic's modern design appeared in the Thanksgiving Day Parade to celebrate Sonic's 20th anniversary.
 * He is also one of the good guys in Super Mario Bros. Z, a Flash series created by Mark Haynes.
 * His favorite drink is Cola.
 * In some media, Sonic the Hedgehog is a Mobian, a kind of Meta-Animal, (also alternatively known as a Superanimal or a Superpowered Animal).