Although Jason is supposed to be a fictitious character, there are striking similarities in the film to a series of grisly murders in Finland in the summer of 1960. Three teens were stabbed to death while camping at Lake Bodom.
The original film's director and co-writer John Carpenter (who also co-wrote 1981's Halloween II with his writing and producing partner Debra Hill) says a creepy encounter he had while attending Western Kentucky University served as inspiration for the fictional serial killer.
Cannibal Holocaust was banned in several countries, including Italy, Australia, the US, Norway, Singapore, and Finland, and though the ban has been lifted in some countries, it continues in many others.
Cannibal Holocaust is one of the goriest movies ever made and even includes real animal deaths on screen, leading to its ban in Italy for violating animal cruelty laws. Cannibal Holocaust also received a five-year ban in America for animal cruelty and extreme violence.