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.

While searching for oil in the deadly swamplands of the Florida Everglades, members of a geological expedition meet an insane doctor who is working on an experiment to create a creature that is part man and part alligator.

A government space experiment into the effects of cosmic rays on animal life goes horribly wrong, creating a mutant monster that terrorizes a rural community.

A mad stage hypnotist Dr. John Basso reverts his beautiful assistant Doreena into the physical form of a prehistoric sea monster she was in a past life. Using this power he attempts to find fame and fortune by predicting a series of murders and then using the monster to carry them out.