Overview
Humongous is a 1982 Canadian slasher film directed by Paul Lynch, and starring Janet Julian, John Wildman, and David Wallace. The story centers on a group of young adults who become stranded on a deserted island, where they are stalked and murdered by a monstrous assailant.
Plot
During Labor Day weekend in 1946, young Ida Parsons is chased into the woods and raped by a houseguest. Her dogs break out of their pen and attack and kill Ida's rapist.
In 1982, brothers Eric and Nick borrow their father's yacht to take their girlfriends, Sandy and Donna, and their sister, Carla, on a weekend outing to St. Martin Island. That night, Eric and Nick discover and rescue a shipwrecked fisherman named Bert. Bert was wrecked offshore Dog Island, the home of lumber baroness Ida Parsons, who has used her family fortune to hole herself up on the island for the past thirty-five years, only making two annual voyages to the mainland for supplies, and never speaking to anyone. Recovering from the onset of hypothermia, Bert tells a campfire story about the wild dogs which roam Ida's island, acting as her sentries.
Donna, Eric, Sandy, Nick, and Bert wreck their boat and wash up on Dog Island. Bert is wounded, and Carla is nowhere to be found. Nick wanders off into the woods, and is killed by a hulking figure. The next morning, Sandy and Eric go onto the island, hoping Ida Parsons will help them get back to the mainland. After they leave the beach, Bert goes into shock, and Donna tries to warm him. The same figure which killed Nick sneaks up behind Donna and Bert, hurling Donna against a rock wall and decapitating Bert.
From Wikipedia (CC BY-SA 4.0).