Carl is the son of Prince Callous and Prince Dingus. He is also the grandson of King Amoeba and Queen Mildew, and the first cousin twice removed of Patrick, Sam, and Gary. He first appears in the family tree in the episode "Rule of Dumb" and the book Mistaken Identity.
He is light purple with light pink lips. He wears glasses, a brown hat with a black stripe, and a light pink one-piece suit.
He is shown on the family tree.