Mr. Mxyzptlk turns Superman, Aquaman and Wonder Woman into the Tin Woodsman, Scarecrow and Cowardly Lion from The Wizard of Oz. After they pass various dangers he reveals his plan was to have them collect for him the ingredients of a potion that will make it so he doesn't have to go back to the 5th Dimension. He still goes back when he says his name backwards because they figured out what he was up to and switched the ingredients.