A dangerous combination of radiation and insecticide causes the unfortunate Scott Carey to shrink, slowly but surely, until he is only a few inches tall. His home becomes a wilderness where he must survive everything from spiders living in the cellar to his beloved cat.
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.
Test space rockets exploding at liftoff and increased reporting of UFO sightings culminate in a direct attempt by alien survivors of a dead, extra-galactic civilization to invade Earth from impervious flying saucers, using ray-weapons of mass destruction.
The arrival in a small mountain town of a dissheveled stranger launches a series of murders committed by some sort of animal. As the town doctor and his daughter attempt to help the stranger, the sheriff investigates the murders; and they uncover a sinister experiment involving two rogue scientists, a car accident victim, his wife and children, and a serum that causes a man to turn into a ravaging werewolf.
Starship C57D travels to planet Altair 4 in search of the crew of spaceship "Bellerophon," a scientific expedition that has been missing for twenty years. They find themselves unwelcome by the expedition's lone survivor and warned of destruction by an invisible force if they don't turn back immediately.
Large star-shaped aliens travel to earth in hopes of warning them about an oncoming catastrophe. To prevent panic about their appearance, one alien takes the form of a popular singer.
A rogue scientist near a small desert town arouses the suspicion of the town's doctor when his lab assistant is found dead from a case of acromegaly, which took only four days to develop. As the doctor investigates, aided by the scientist's new female assistant, they discover that something is devouring local cattle and humans in increasingly large quantities.
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.
In a tributary of the Amazon, a monster – half-man, half-fish – is captured and placed in a reservoir in a Florida national park to be observed by scientists.
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.
As a result of nuclear testing, gigantic, ferocious mutant ants appear in the American desert southwest, and a father-daughter team of entomologists join forces with the state police officer who first discovers their existence, an FBI agent and, eventually, the US Army to eradicate the menace, before it spreads across the continent — and the world.
When scientists exploring the Amazon River stumble on a “missing link” connecting humans and fish, they plan to capture it for later study. But the Creature has plans of his own, and has set his sights on the lead scientist's beautiful fiancée, Kay.
The residents of a small town are excited when a flaming meteor lands in the hills, until they discover it is the first of many transport devices from Mars bringing an army of invaders invincible to any man-made weapon, even the atomic bomb.
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.