An evil, ultra-high performance, very advanced Badnik version of Sonic the Hedgehog that was created as a secret weapon by Dr. Eggman for the sole purpose of destroying the blue hedgehog. Modeled with extreme accuracy after Sonic, Metal Sonic not only resembles his organic doppelgänger, but can also imitate his moves and achieve speeds matching and even exceeding the hedgehog's own. The brainchild of Eggman, he is by far his greatest creation and one of his "magnum opuses". First deployed during the Little Planet incident, Metal Sonic confronted Sonic in battle and lost, though he would repeatedly return to challenge Sonic and his allies as Eggman's "too-sharp sword".