According to Warwick Davis, the film had the largest ever casting call for "little people" at the time. Between 225 and 240 actors were hired for the film.
On the audio commentary, Warwick Davis explains that the question he gets asked the most was how working with Val Kilmer was like. During the 1990s, Kilmer had developed a reputation of an actor with whom it was difficult (if not impossible) to work. However, Davis said he has very fond memories of working with Kilmer, describing him as having a great, "wacky" sense of humor and being very passionate and dedicated to the job. Kilmer also adlibbed much of his dialogue.
George Lucas specifically wrote this film for Warwick Davis after meeting him on the set of "Star Wars: Episode VI - Return of the Jedi (1983)."
The devil dogs were actually Rottweilers in rubber masks and suits.