On its initial release in its home turf of New Zealand, this movie earned more per screen than Batmans Rückkehr (1992).
300 liters of fake blood was used in the final scene of the film.
The BBFC loved the film and found the gore so comical and inoffensive that they seriously considered granting it a "15" certificate. In the end they determined that the sheer quantity of gore would confound expectations at "15" and therefore rated it "18".
The movie is said to be the bloodiest of all time (measured in amount of film blood used during the production).
The rental in Sweden (and probably other countries as well) came with supplemental vomit bags.
Forrest J. Ackerman: as more or less himself; the tourist at the zoo who takes a photo of Lionel's mother squishing the rat monkey's head with her shoe.