On Halloween night, Samantha and her friends are enjoying a lively party at the Bowl-o-Rama. The festivities take a dark turn with the unexpected arrival of the Chubbies. These bizarre and lustful creatures hail from the far-off planet of Snerd, where sexual activity is forbidden. Their mission is to conquer Earth by infiltrating human bodies through any available opening. The celebration quickly transforms into a nightmare as the teenagers find themselves trapped by the Chubbies, leading to a thrilling and comedic battle to protect themselves from these invasive beings.