Knuckles is an echidna with spiky knuckles. He is the last of his kind. He lives on Angel island where he protects the master emerald. When Sonic The hedgehog came Eggman told knuckles that he was here to steal the master emerald, so they teamed up to defeat Sonic. In the end the truth was revealed and sonic beat Eggman once again even with Metal sonic. Knuckles then became a friend of sonic and an enemy of Eggman.