In The Neanderthal Man, a mad scientist transforms himself into a prehistoric caveman, his cat into a saber-toothed tiger, and his housekeeper into an ape person. He alienates his daughter and girlfriend in the process. And unwittingly kills several of his friends.
The Alligator People (1959) starring Beverly Garland, Richard Crane, Lon Chaney Jr.
Synopsis of The Alligator People
In The Alligator People, a newlywed husband abandons his young wife (Beverly Garland) on their wedding day. Distraught, she traces him to his ancestral home in the bayous of Louisiana, where, amid the swamps and deadly undergrowth, she discovers a terrible secret. Her husband was saved from death by an experimental medical procedure involving serum derived from alligators and now he’s developing horrifying side-effects. She’ll face any danger to help him but soon discovers her love may not be enough.