A refugee Soviet scientist arrives at a desert airport carrying secret documents, but is attacked by a pair of KGB assassins and escapes into the desert, where he comes in range of an American nuclear test and is transformed into a mindless killing beast.
Dr. Decker returns from Africa after a year, presumed dead. In that year, he discovered a way of growing plants and animals to an enormous size. He brings back a baby chimpanzee to test out his theory. As he has many enemies at home, he decides to use his chimp, 'Konga', to 'get rid of them'. Then Konga grows to gigantic proportions and wreaks havoc all over London!
A portion of the tail of a prehistoric reptile is discovered in Denmark. It regenerates into the entire reptile, which proceeds to destroy buildings and property and generally make a nuisance of itself. It can fly, swim, and walk, and has impenetrable scales, which makes it difficult to kill.
After being thrown out of medical school for ethical violations, Dr. Peter Blood returns home to a small Cornish village, where he sets up a research laboratory in a secluded cave. There, he attempts to revive the dead, using kidnapped humans -- who he views as unworthy of life -- for their body parts, specifically, their hearts.
Harold Gern, a shady businessman from New York, is spending a holiday in Puerto Rico with his attractive wife Evelyn. They are joined by Martin Joyce, Harold's lawyer, who has come to discuss the latest indictment. Harold invites him along on a boat trip during which all three try out some newly bought scuba diving equipment. When they resurface, they find out that the world has changed forever.
An ex-major forces a scientist to develop a invisibility formula, with which he plans to create an invisible army and sell it to the highest bidder. However there are side effects to the formula.
The head of a major cosmetics company experiments on herself with a youth formula made from royal jelly extracted from wasps, but the formula's side effects have deadly consequences.
In one of his rare performances without Bud Abbott, Lou Costello plays a rubbish collector and inventor. When radiation in a nearby cave turns his girlfriend into a giantess, antics ensue as he tries to shrink her using one of his inventions.
A pathologist experiments with a deaf-mute woman who is unable to scream to prove that humans die of fright due to an organism he names The Tingler that lives within each person on the spinal cord and is suppressed only when people scream when scared.
A backwoods game warden and a local doctor discover that giant leeches are responsible for disappearances and deaths in a local swamp, but the local police don't believe them.
Trapped on a remote island by a hurricane, a group discover a doctor has been experimenting on creating half sized humans. Unfortunately, his experiments have also created giant shrews, who when they have run out of small animals to eat, turn on the humans.
A college paleontology professor acquires a newly discovered specimen of a coelacanth, but while examining it, he is accidentally exposed to its blood, and finds himself periodically turning into a murderous Neanderthal man.
Teenagers from a small town and their high school science teacher join forces to battle a giant mutant spider, living in a cave nearby and getting hungry.
A man and wife are terrorized by Mad Scientist Dr. Callistratus who was executed but has returned to life with a heart transplant. Along with his crippled assistant Carl, the 'anemic' Mad Scientist, believed to be a vampire, conducts blood deficiency research on the inmates of a prison hospital for the criminally insane to sustain his return to life.
Glenn Manning, "The Amazing Colossal Man," believed dead after falling from the Hoover Dam, reemerges in rural Mexico, brain damaged, disfigured, and very angry.