Joe's shark menservant once was a basic shark, but was mildly corrupted by an intelligence potion, While enough to make him speak, he still thinks like what sharks usually think, making him like your basic dim-witted side-kick.
Despite betraying Joe, Malefor revived him, ensuring that the shark will remain loyal to him, and made the shark the Dark Spawn shark of Gluttony,in honor of his tendency to eat anyhing small enough to fit his un-forgiving jaws.