As an actor, Oz appeared in one scene as a Prison Storeroom Keeper in "The Blues Brothers" (1980), directed by John Landis. He appeared in a similar role and scene in "Trading Places" (1983), also directed by Landis. He had roles in several other Landis films including "An American Werewolf in London" (1981), "Spies Like Us" (1985), "Innocent Blood" (1992) and "Blues Brothers 2000" (1998). In 2001 he had a voice acting role in the Pixar film "Monsters, Inc." as Randall's scare assistant, Fungus. In 2005, he had a minor part in the Columbia film "Zathura" as the voice of the robot.