Per the movie case: "Mysterious disappearances and the strange circumstances surrounding them grip the swamp patrolled by Game Warden Steve Benton (Ken Clark). while searching the back country for illegal poachers, Benton and his girlfriend Nan Greyson (Jan Shepard) come across a dying moonshiner with mysterious wounds and major blood loss. Adding to this evidence is the eye witness report from a man stating his wife and her lover were dragged into the swamp by some mysterious creatures. When more hunters turn up missing, Benton decides it's time to investigate."
Are you totally sold yet?! Yeah, I know you're curious.
Here, watch the entire movie now, compliments of the Internet Archive!: