I Was Bitten (2008)
S04E10 Wishbones
Episode Overview
When Grim's robe emerges from the laundry, Billy and Mandy discover Thromnambular, a chatty skull adorned with ruby eyes and a number nine on his forehead. Grim explains that this enchanted artifact is trapped on Earth and can only gain freedom by granting nine wishes. Curiously, Mandy questions why Grim hasn't made any wishes himself. Grim reveals that the skull has a tendency to twist the wishes, ultimately bringing misfortune to the one who wishes.