Chaos (Sonic the Hedgehog)

Chaos is a mutated Chao from the Sonic the Hedgehog series, who debuted in the game Sonic Adventure, later remade into Sonic Adventure DX: Director's Cut for the Nintendo GameCube. Originally made to assist Dr. Robotnik in conquering the world, Chaos turned against Robotnik, which forced Robotnik to partner up with Sonic. Chaos has several differant forms, including Perfect Chaos, the final boss of Sonic Adventure DX, who could only be defeated by Super Sonic.