Sonic the Hedgehog
Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ, Sonic the Hedgehog) is the main character of the Sonic the Hedgehog games and the mascot of Sega. Sonic was first introduced by Sega in 1991 in the game Sonic the Hedgehog to combat Nintendo's mascot, Mario. He is often thought of as Mario's unofficial rival, though they have appeared in games together. He makes his first Smash Bros. appearance in Super Smash Bros. Brawl, as one of the third-party characters, the other being Solid Snake. Sonic was announced to make a return in Super Smash Bros. 4 during a Nintendo Direct on October 1, 2013.
Sonic is a male, 15 year-old, anthropomorphic hedgehog. He has spiky blue hair, green eyes, and red and white running shoes with gold buckles. He is only one meter (3ft, 3in) tall (though, in his appearance in Super Smash Bros. Brawl, his height is obviously increased). As his name suggests, he is capable of running at supersonic speeds. The self-described "coolest, blue hedgehog alive," he has a bit of an attitude and is impatient, but cannot resist helping someone in need. He values freedom above all else and constantly campaigns to free animals imprisoned by the evil Dr. Ivo "Eggman" Robotnik. Generally speaking, Sonic loves being able to do what he wants and loathes being constrained. He gathers golden rings for energy, and when he collects the seven Chaos Emeralds, he becomes Super Sonic, with yellow fur and red eyes, capable of flight. Most of the time, every challenge he faces seems enjoyable to him; another chance to get moving. However, he does take time to relax once in a while. Early Western profiles sometimes portrayed Sonic as being from the imaginary planet Mobius, while Japanese profiles (which Western territories would follow starting in 1999 with Sonic Adventure) state that his birthplace is Christmas Island, a real-world dependant territory of Australia.
Although Sega and Nintendo were hardware and software rivals at the release of the Nintendo GameCube, Sonic's creator Yuji Naka claimed that there existed a possibility of including Sonic in Melee, though time constraints apparently caused these plans to fall through. It would later be revealed that both Shigeru Miyamoto and Masahiro Sakurai would have been fine with the idea of Sonic in Melee.
While unofficial, an infamous hoax claimed that Sonic and Tails were unlockable in Melee. While later proven false, the hoax remains well-known in both the Smash Bros. community and the wider world of gaming.
In Super Smash Bros. Brawl
Sonic is a playable character in Brawl and was confirmed on October 9th, 2007. He is the fastest character in the game, with attacks based largely on his earlier platforming games. His appearance is based on the "modern" Sonic appearance which debuted in Sonic Adventure. Sonic's Final Smash, Super Sonic, is a very powerful transformation and it allows him to fly around the stage at incredible speed. Sonic also appears very late in the game's story mode, helping to defeat Tabuu in the final battle.
Sonic is ranked 22nd on the current tier list in D tier due to his severe inability to KO efficiently, which nearly counters out his amazing frame data and movement options almost entirely.
The world's fastest hedgehog, who can run at supersonic speeds. Generally speaking, he loves being able to do what he wants and loathes being constrained. Holding still is something he would never consider. He's got a bit of an attitude but can't pass by someone in trouble. When he collects the seven Chaos Emeralds, he transforms into the mighty, gold Super Sonic.
In Super Smash Bros. 4
Sonic was confirmed to be a returning playable character in Super Smash Bros. 4 during the Nintendo Direct of October 1st, 2013. He retains the same four special moves from Brawl, but his voice changes. Rather than Jason Griffith who previously voiced Sonic in Brawl and previous Sonic games (2005-2010), he is now voiced in SSB4 by Roger Craig Smith, who has taken the role since Sonic Free Riders and Sonic Colors (2010-present). His design is similar to his appearance in Sonic Lost World, as his quills are a bit smaller and is a brighter shade of blue than previously. Sonic is the first and so far only third-party character in the series to be a veteran.
Sonic was heavily buffed in the transition from Brawl to SSB4, which shows in his tier list ranking of 6th out of 56. Sonic had his previously weak KOing power improved significantly, and also retains his fast speed and mobility. He also has an improved combo game. These strengths give him a powerful neutral game. While he received nerfs to his recovery as well as added lag on some moves, the notable improvements to his power have resulted in higher viability compared to Brawl, and he has seen strong representation and great results in tournaments.