I Was a Teenage Zombie (1987)
The plot centers around six friends trying to score some weed to loosen up their prom dates. It's been a very dry year, so only dealer Moose ... has the only "weed" in town. His product is subpar to say the least, so the buddies decide to get a refund, which Moose refuses to honor. This leads to the guys killing Moose, and disposing of his body in a contaminated river. Well, the contamination brings Moose back from the dead, as a crazed revenge seeking zombie. After Moose kills baseball stud Dan(a remarkable performance by Michael Rubin), his friends decide to dump his body into the river, thus re-animating him to serve as undead protection from the zombie Moose.
This film is very clever, in the league of Evil Dead and Re-Animator, and should be considered a great cult film. Personally, my favorite scene was when Dan day-dreams about swatting a clutch homerun, that kills the crazed Moose. Well worth a look for people who like witty comedy sprinkled with their horror. (IMDB BloodTheTelepathicDog)