A backwoods game warden and a local doctor discover that giant leeches are responsible for disappearances and deaths in a local swamp, but the local police don’t believe them.

An astronaut returns to Earth as the no-pulse host of an alien monster’s embryos; he is discovered by a loony farmer who find ways to feed his new critter.

Lt. Robin Crusoe is a navy pilot who bails out of his plane after engine trouble. He reaches a deserted island paradise where he builds a house and begins to…