Thirteen years ago, at the Halloween Pumpkin Prom, the infamous Lawnmower Killer went on a brutal rampage, murdering several high school students, including Mary Graves' older sister, traumatizing her for life. Now, after the unexpected escape of a prisoner from the state mental hospital, who may or may not be the killer, it's up to hard-nosed gumshoe Dick Harbinger to solve the case before the Lawnmower Killer seeks out a new slew of victims at the upcoming Pumpkin Prom, that is if anyone is able to survive the hilarious horror hijinks leading up to it! Thanks to pieces such as Student Bodies and Saturday the 14th comedy-horror was big business in the early 80s and Wacko from 1982 was one of the better ones. Exploitation director Greydon Clark delivers a mad mix of spoof and shocks whilst his A-list cast, which includes George Kennedy (Charade), Joe don Baker (Goldeneye, Fletch), Charles Napier (The Blues Brothers, Supervixens) and Stella Stevens (The Poseidon Adventure) play the movie as straight as they can.