In 1946, a woman is raped during a Labor Day party. 36 years later, a group of teens become stranded on Dog Island after their yacht hits some rocks. The group quickly discovers there is something worse than wild dogs living on the island.
While watching Humongous, slasher fans should look for the many Scooby-Doo references. The teens are a blonde guy (David Wallace), his model girlfriend (Janet Julian), a brainy girl with glasses (Janet Julian), a stoner (John Wildman), and everyman's best friend (Joy Boushel). The smart chick loses her glasses just like Velma. The gang even splits up to look for clues.
The most sympathetic characters are Donna the slut and the killer. Poor Donna never fits in with the rich kids and most of the characters are mean to her. She has trouble communicating with others and relies on her breasts in most situations, even when gathering food. The killer, a giant mongoloid, only kills because he is hungry. His cruel mother forces him to live in a rat infested cellar. There are a few hints that his mother tortured him because of his deformities.
The biggest flaw in Humongous is the terrible lighting. Most of the action scenes are waaay to dark to see what's happening. Even the killer's face is blotted out, so the viewer never knows just how monstrous he looks. Some suspense is killed because the viewer knows more than the characters. We know a brute is stalking the kids, so the big revelation concerning the killer's identity lacks impact.
Director Paul Lynch and writer William Gray, the tag team that created Prom Night, filled Humongous with many slasher staples; including killer POV shots, a woman surviving by dressing like the killer's dead mother, and the line "I killed him. It's all over." If you like the hulking, deformed slasher subgenre (Hell Night, The House on Sorority Row, The Prey), then you should enjoy Humongous.