The good campy fun in this sci-fi horror movie really begins when the head of a racist mad scientist (Ray Milland) is sewn onto the shoulders of a large black convict (Rosie Grier) and the two heads begin fighting--literally trying to punch each other out--to control their shared body. The whole mess begins because the brain surgeon suffers from terminal cancer. He reasons that he will survive if he can transplant his head onto the shoulders of another. He and his team begin experimenting. First he has his head sewn to a gorilla (featuring a simian created by fledgling make-up artist Rick Baker). Something goes terribly wrong, he goes into a coma and when he wakes up, he finds himself having a permanent tete-a-tete with the wrongfully convicted Grier.~ Sandra Brennan, All Movie Guide