An astronaut goes into space with a chimpanzee. When they return to Earth after their orbit, it is discovered that the chimp has the brains of the astronaut, and the astronaut has the brains of the chimp. Complications ensue. Frankie Avalon, Deborah Walley, Cesar Romero, Fred Clark, Gale Gordon, Harvey Lembeck, John Ashley Added on Amazon Prime 2022-05-28.