'It's Alive!' (1969)

In this sci-fi film a loony farmer finds a prehistoric monster hiding in a cavern on his land. To feed his newest critter, the farmer kidnaps three people. The three desperately try to escape and finally, one of them succeeds.

Director:

 Larry Buchanan

Stars:

 Tommy Kirk, Shirley Bonne, Bill Thurman - via IMDB

https://archive.org/details/ItsAlive