Yathzee is a character that appears in the episode, "Shirt Herpes". He is a demon with red skin, two wings, three horns protruding from his head, and a long tail. He speaks in a deep, raspy voice and is skilled at playing the guitar.
In "Shirt Herpes", Carl convinces Shake to take his newly bought shirt, by telling him a story in which he decapitates Yahtzee and kills his three demon brethren to obtain the apparel. Eventually, after wearing the shirt, Shake starts to have dreams about the demons, with Yahtzee sticking him the lake of fire, completely melting his skin. After the shirt starts to fuse with Shake's skin, he has another dream in which Yahtzee tells him that he needs to give the piece of clothing to another or will enter a coma for the rest of his life, and in that coma, he will be raped by a giant octopus in his dreams. Unfortunately, Shake is unable to get rid of his shirt, forcing him to enter a coma while being continuously raped by an octopus in his nightmares.
- His name is a reference to the board game, "Yahtzee"