The Thing with Two Heads

Dr. Maxwell Kirshner (Ray Milland) arrives at a mansion as a passenger in a wheelchair; once inside Kirshner asks if his experiment has been a success, and is told by an orderly that it has been. He is taken to the basement, where we see the experiment is in fact a two-headed gorilla (Rick Baker) that Dr. Kirshner has created. The experiment is to determine whether two heads can survive on a single body. Dr. Kirshner has done this because he has not much longer to live and wants to transplant his still living head from his lifeless body onto a donor so that he may continue living and continue working as the world's most successful surgeon.