Earth vs. the Flying Saucers

A flying saucer hidden in a Red Chinese peasant village is sought by teams from the United States and U.S.S.R. On finding it, they band together to explore the saucer and take a trip into space.

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.

Astronomer Shinichi Tachibana has a secret identity as the superhero "Iron Sharp" and is well beloved by children. When they are attacked by a group of metallic aliens, Iron Sharp drives the aliens away. The resourceful Tachibana helps develop an electric barrier to block the aliens from coming to the Earth. After several losses by the aliens, they announce that they will invade the Earth, throwing the world into a state of panic.

A heroic expedition braves snow-whipped precipices and discovers the dreaded humanoids. But wait – these are extraterrestrial yetis who zipped in from outer space to conquer Earth by melting the polar ice caps with high-energy proton fields. Will mankind be global-warmed into surrender?

A young alien falls for a pretty teenage Earth girl and they team up to try to stop the plans of his invading cohorts, who intend to use Earth as a food-breeding ground for giant lobsters from their planet.