- Fake Nationality: Richard E. Grant (a British citizen of Dutch/Afrikaner ancestry) plays Scotsman Redferne.
- Hey, It's That Guy!: When you mess with Jerry, you go in the grinder.
- The Other Darrin: Bruce Payne replaced Julian Sands as the title character in Warlock III: The End of Innocence.
- The Shelf of Movie Languishment: Warlock was completed in 1988 and was set to open in May 1989, but New World Pictures went under and it took two years to find a domestic release (the film did open in 1989 outside the US).
- What Could Have Been: Kassandra was originally supposed to look a lot older than she does, but like William Shatner during filming of the Star Trek: The Original Series episode "The Deadly Years," Lori Singer had problems with the makeup - not for reasons of ego (Shatner didn't want to look old, even though that was kind of the point) but because the intended appliances made her claustrophobicnote , so they had to be drastically toned down.