Metal Sonic is a robot anthropomorphic hedgehog  built of blue metal. He has a yellow circular depression in his chest with a black center, mirroring the peach skin on Sonic's chest. His head has metal fins resembling Sonic's quills and a pair of triangular "ears." Metal Sonic has a muzzle, shoulder plates, upper arms, legs, and fingers made out of silvery metal. His palms are black, while the backs of his hands are square yellow plates. 