Trivia: When a human warrior is pulled from his horse and thrown to the ground by an orc during the first battle between the orcs and the humans, he yells a Wilhelm scream.
Trivia: When Lockhart is in the sensory deprivation tank, the nurse that does a poor job of keeping an eye on him is reading "Der Zauberberg" by Thomas Mann, which obviously has at that point a common premise with the movie (the main character goes to a sanatorium in the Alps just as a visitor but ends up as an inmate). The novel was inspired by Mann's visit to his wife at a Swiss sanatorium which happened in 1912, same year as the picture fully unveiled in the finale.
Trivia: Jason Mewes was originally set to play the "Brahtzies", but had to drop out due to finding the makeup required for the roles far too claustrophobic.
Trivia: Despite receiving prominent billing, Jonah Hill is only in the film for three minutes.
Trivia: When one of the Galactic Rangers' robots falls off a platform, he yells a Wilhelm scream.
Trivia: Spoilers: At one point during the climax, you can briefly see a creature with long arms and legs barging through a doorway for a split-second. Many viewers assumed that this was the titular "Blair Witch." However, the screenwriter has stated that any creatures/specters visible in the film are meant to be grotesque manifestations of the witch's past victims (with the long-limbed creature presumably being Heather given she's in the place where Heather died), and that as stated earlier in the film by one of the characters, nobody can actually "see" the witch herself.
Trivia: The film was originally written to be an introspective, existential dramedy geared towards adults about a troubled man who is turned into a cat. As originally planned, the cat also wouldn't speak/the audience wouldn't hear his thoughts. However, after a change in leadership at the studio, the film was rewritten into a more generic family movie.
Trivia: On Paterson's bed stand, there is a photo of a younger Paterson during his military service. This is an actual photo of Adam Driver from his time in the United States Marine Corps. (00:01:40)
Trivia: When Tripp is talking to his truck and he says "you'll have the heart of an elephant", it refers to the nickname hot rodders called the 426 Hemi V8 from 1966-1971, called the "Elephant Motor" for its massive size and weight. It also made 425 horsepower, which Tripp incorrectly states that the engine he pulled out of the truck made.