Monsters from space attack earth, two scientists and a couple of teenagers try to stop the extraterrestrial invaders.
An outlaw motorcycle gang is headed by two couples (Bambi Allan, Jennifer Bishop, Bill Bonner and Bryan West). The gang is badly hurt by a botched robbery and the four stars, the only survivors, eventually head to Mexico, where they have to combat a gang run by a sadistic Mexican (Rafael Campos).
Tommy Kirk leads his fellow Martians to Earth on an interplanetary quest for females. Kirk proves that Martians have impeccable taste when one of his first conquests turns out to be sexy scientist Yvonne Craig.
A misguided scientist enables an alien from Venus named Zontar to come to earth in order to "help solve man's problems". However, as soon as Zontar arrives on Earth, it quickly becomes obvious that the three-eyed, bat-winged, skeletal black creature has a hidden agenda.
A teenager and his girlfriend must save the world from "eye" aliens after their attempts to convince authorities of an invasion fall on deaf ears.