In 19th century England, a noted brain surgeon rescues a former student from being hanged on a false conviction for murder, and spirits him away to an ancient, repurposed abbey far in the countryside. There, he connives his pupil into assisting him in mapping the functions of the various parts of the human brain, using living subjects who are under a terrible animation-suspending drug called "black sleep". Subsequently, the student, along with the daughter of one of the subjects, discover that most of these subjects have survived but are being kept in a dungeon-like cellar, in various stages of physical and mental derangement...
A scientific experiment involving subjecting a corpse to an extreme charge of electricity accidentally revives an executed criminal and makes him impervious to harm, allowing him to seek revenge on his former partners, and deal similarly with anyone else who gets in his way.
A marine biologist and a government agent investigate mysterious deaths and rumors of a sea monster in a secluded ocean cove, and find themselves involved with a marine biology professor conducting secretive experiments, international spies trying to steal his secrets, a radioactive light on the sea bottom, and the malevolent thing which guards it.
After a nuclear attack, an unlikely group of survivors, including a geologist, a crook and his moll, and a prospector, find temporary shelter in the remote-valley home of a survivalist and his beautiful daughter, but soon have to deal with the spread of radioactivity - and its effects on animal life, including humans.
In 1960, four American scientists travel to a planet that has just entered Earth's solar system to see if it's able to support an Earth colony. They find an oxygen atmosphere, a lush earth-like forest, and earth-like animals living around a potable fresh-water lake.
Murders, with victims dying from spines broken by brute strength, erupt in the city and the killers, when encountered, walk away unharmed by police bullets which strike them. A police doctor's investigation of the deaths leads to the discovery of an army of dead criminal musclemen restored to life, remotely controlled by a vengeful former crime boss and a former Nazi scientist, from the latter's laboratory hidden in the suburbs.
A giant octopus, whose feeding habits have been affected by radiation from H-Bomb tests, rises from the Mindanao Deep to terrorize the California Coast.
Dr. Eric Vornoff, with the help of his mute assistant Lobo, captures twelve men for a grisly experiment; His goal to turn them into supermen using atomic energy. Reporter Janet Lawton, fiancée of the local lieutenant, vows to investigate Vornoff's supposedly haunted house.
Ann Dexter, daughter of an itinerant Haiti waterfront character, Carl Dexter, brings a golden idol, which her father her stolen at a voodoo ceremony, to Bill Buchanan, who is known along the waterfront as a man eternally on a treasure hunt. He agrees to let Ann accompany him in search of the treasure after a native he befriended gives him directions and certain voodoo secret charms. They follow an underwater passage to an island where they find a Pagan tribe. They learn that the golden idol is a burial symbol representing the dead and that hundreds of idols are at the bottom of the sacred burial lake.
Julie, an American on vacation in Mexico, spots a giant, one-eyed amoeba rising from the ocean, but when she tries to tell the authorities, no one believes her. She finally teams up with a marine biologist in an attempt to destroy it.
Don Gallico is an inventor of stage magic effects who aspires to become a star in his own right. Just before his first performance his act is shut down by capricious manager Ross Ormond who wants Gallico's brilliant buzz saw effect for the act of The Great Rinaldi, an established star. With this defeat, and the humiliation of having already lost his wife Claire to Ormond, Gallico decides it is time to take matters into his own hands.
Eight people at a remote Scottish inn find themselves confronted by a woman from Mars, who has landed her flying saucer for repairs but intends to soon conquer the Earth and enslave its men for breeding purposes.
Atomic scientist/pilot Doug Martin is missing after his plane crashes on an reconnaissance mission after a nuclear test. Miraculously appearing unhurt at the base later, he is given sodium amethol, but authorities are skeptical of his story that he was captured by aliens determined to conquer the Earth with giant monsters and insects. Martin vows to use existing technology to destroy them.
Thieves break into a scientist's laboratory to steal a secret formula, and in the process they kill his daughter. Enraged, he develops a formula that will turn an extremely ugly woman into a spectacular beauty, and then uses the woman to take his revenge on those responsible for his daughter's murder.
London, 1888: on the night of the third Jack the Ripper killing, soft-spoken Mr. Slade, a research pathologist, takes lodgings with the Harleys, including a gloomy attic room for "experiments." Mrs. Harley finds Slade odd and increasingly suspects the worst; her niece Lily (star of a decidedly Parisian stage revue) finds him interesting and increasingly attractive. Is Lily in danger, or are her mother's suspicions merely a red herring?
A scientist develops a formula which will cause animals to regress to the form of their primitive ancestors, and tries it on himself with disastrous results.
A mad scientist, Dr. Aranya (Jackie Coogan), has created giant spiders in his Mexican lab in Zarpa Mesa to create a race of superwomen by injecting spiders with human pituitary growth hormones. Women develop miraculous regenerative powers, but men mutate into disfigured dwarves. Spiders grow to human size and intelligence.