Shadow is an Unknown character that first appeared in The Shadow Gem.
Despite his name, Shadow Gumball doesn't exactly look like Gumball. He has Sullvan's head, body, and arms. He has Gumball's legs, ears, and tail. He has completely white eyes, and always smiles. He also has a slouched position, like Fangy.
Not much is known about him, except that he is always in a still position. He also Teleports.
Season 2 Edit
Shadow Gumball first appeared in The Shadow, where Sullvan first discovered him in the woods. He was later seen again when he was talked about in the woods. Not much is known about him yet.