Overview
Humanoids from the Deep (released as Monster in Europe and Japan) is a 1980 American science fiction horror film starring Doug McClure, Ann Turkel, and Vic Morrow. Roger Corman served as the film's uncredited executive producer, and his company, New World Pictures, distributed it. Humanoids from the Deep was directed by Barbara Peeters and an uncredited Jimmy T. Murakami.
Plot
Anglers from the fishing village of Noyo, California, catch what appears to be a monster. The young son of one of the anglers falls into the water and something unseen drags him under the surface. Another angler prepares a flare gun, but he slips and accidentally fires it into the deck, which is soaked with gasoline dropped earlier by the boy. The vessel bursts into flames and explodes; everybody aboard is killed. Jim Hill and his wife Carol witness the explosion. Later, Jim and Carol's dog goes missing and the pair finds its dismembered corpse on the nearby beach.
The following day, teenagers Jerry Potter and Peggy Larson go for a swim at the beach. Jerry is abruptly pulled under the water. Peggy believes it is a prank until she discovers his mutilated corpse. Peggy screams and tries to reach the beach, but a monstrous figure drags her across the sand. The humanoid creature tears off her bikini and rapes her.
From Wikipedia (CC BY-SA 4.0).