Island of the Fishmen ★★★

Well if it's any comfort to you, nobody leaves this island unless I want them to.
-Edmond Rackham

This is basically a cross between The Island of Dr. Moreau and Creature from the Black Lagoon, but saying that isn't anything clever. It's impossible not to see it. The plot of the movie is basically lifted directly from Moreau and the Fishmen look like carbon copies of Gill-Man (Black Lagoon). Still though you have Barbara Bach and some pretty cool gore sprinkled out through the film.

Part of:
Horroctober VIII: The Night Mrs. DuLac Came Out of the Grave