American professor John Holden arrives in London for a conference on parapsychology only to discover that the colleague he was supposed to meet was killed in a freak accident the day before. It turns out that the deceased had been investigating a cult lead by Dr. Julian Karswell. Though a skeptic, Holden is suspicious of the devil-worshiping Karswell. Following a trail of mysterious manuscripts, Holden enters a world that makes him question his faith in science.
A crazed teacher at a respectable girls' school draws power from a medallion she has obtained from the Carpathian Mountains, and uses it to experiment telepathically on the school's newest young pupil.
A pretty young Mexican girl returns to her hometown to make funeral arrangements for her beloved aunt, who has just died. Soon she begins to hear disturbing stories about the town being infested by vampires, and she eventually begins to suspect that her remaining aunt and the mysterious next-door neighbor may be involved.
A young woman discovers she is the daughter of the infamous Dr. Jekyll, and begins to believe that she may also have a split personality, one of whom is a ruthless killer.
A small town doctor mistakenly ingests an experimental drug made from the blood of vampire bats which transforms the kindly medic into a bloodthirsty monster.
Global panic ensues when it is revealed that a mysterious UFO is actually a giant turkey-like bird that flies at supersonic speed and has no regard for life or architecture.
Baron Victor Frankenstein has discovered life's secret and unleashed a blood-curdling chain of events resulting from his creation: a cursed creature with a horrid face — and a tendency to kill.
A test rocket carrying wasps to outer space, to study the effects on them of weightlessness and radiations, crashes out of control back to Earth, into the jungles of Africa. The two astrobiologists in charge of the test mount an expedition to the Darkest Continent to retrieve their experiment, only to find the wasps have grown to giant size which are panicking all forms of life as they quest for food.
A wealthy business man discovers he has a brain tumor and seeks medical help. The business man finds a scientist experimenting with transplanting monkey heads on different monkey bodies. The business man decides to steal the head of Nostradamus from the prophet's crypt.
Deep in the jungles a mad scientist is using the natives' voodoo for his experiments to create an indestructible being to serve his will. When a party of gold seekers stumbles upon his village, the scientist realizes that Marilyn the expedition's evil leader is the perfect subject for his work.
Two psychics place a prostitute under hypnosis in order to learn about her past-life experiences. When they unwittingly send her back in time, she finds herself in the Middle Ages, suspected of being a witch and on the verge of being executed.
A group of scientists travel to a remote island to study the effects of nuclear weapons tests, only to get stranded when their airplane mysteriously explodes. The team soon discovers that the tests have given rise to crabs mutated into intelligent, impervious, telepathic giants intent on increasing their numbers by breeding, then travelling to populated areas to feed, and which do not intend to be stopped by their discoverers.
When the first manned flight to Venus returns to Earth, the rocket crash-lands in the Mediterranean near a small Italian fishing village. The locals manage to save one of the astronauts Colonel Calder, the mission commander. A young boy also recovers what turns out to be a specimen of an alien creature. Growing at a fantastic rate, it manages to escape and eventually threatens the city of Rome.
Connie Hayward mounts an expedition into the Himalayan Mountains looking for her brother, who has not returned from a previous trek trying to locate the Yeti, or "Abominable Snowman". Arriving at her brother's last-known camp Connie and her companions find only a strange old guide, Varga. They are soon attacked by gigantic Snowmen but are not half as surprised as when Vargas reveals his secret origin and the plans he has for Connie.
An American reporter smells a story when he is stranded in an Iron Curtain country where the local dictator is using gamma rays to transform children into mutated henchmen.
A woman believes herself to be the reincarnated spirit of an ancient prince's lover. Meanwhile, a murderer turns out to be the reincarnated spirit of the prince himself.