Seelkadoom is a black Hedgehog, with blue stripes all over his quills, representing the stripes that Shadow has, and Sonic's fur color. The quills themselves appear to be a combination of Sonic and Shadow's, with the top ones resembling Shadow's and the bottom ones resembling Sonic's. He has his skin shown on his arms and belly, representing Sonic's appearance. He has a pair of sneakers that look like Sonic's, only they are colored gray instead of red. He also has the gloves and cuffs of Sonic. 