Villian(s)  Rampaging primate

Actor(s):  Christopher Atkins, Amanda Wyss, Ari Meyers, Roddy McDowall

Brief Description  Shakma (1990) is an American natural horror B-movie directed by Hugh Parks and Tom Logan. The film has earned a dedicated cult following for its unique and bizarre premise: a killer baboon hunting down live-action role-players inside a locked medical research building. Unlike many monster movies that rely on puppets or costumes, Shakma utilized a real, live baboon (handled by Typhoon) for nearly 98% of the animal's screen time. The chaotic editing and the genuine aggression of the animal make the attack sequences surprisingly intense and terrifying.

Plot:
The film takes place over the course of a single day and night at a medical school facility. A group of pre-med students and their professor, Sorenson, have been conducting aggression experiments on a Hamadryas baboon named Shakma. After being injected with an experimental drug intended to reduce aggression, the serum has the exact opposite effect, driving the primate into a state of uncontrollable rage. Believing the animal has been safely euthanized or sedated, the group decides to stay after hours to play an elaborate, Dungeons & Dragons-style live-action role-playing game (LARP) throughout the building's corridors. Professor Sorenson locks the external doors to secure the facility for the game. However, Shakma awakens, escapes his enclosure, and begins systematically stalking and slaughtering the trapped participants one by one.