Trivia: In an interview, the director stated that hoverboards were real, but they weren't on the market because parents didn't like the idea of floating children. He said this as a joke, but this didn't stop mass hysteria as thousands of kids went from store to store looking for hoverboards.
Trivia: The sound of Vigo growling is exactly the same growl that the terror dogs from the first Ghostbusters make.
Trivia: When David Banner is dreaming about his trial, the jury foreperson is played by The Incredible Hulk creator, Stan Lee.
Trivia: The dead sailor harbouring a live crab, spooking Jammer out of his wits in the sunk submarine, is director James Cameron's younger brother Mike. The scene had to be shot several times to get it right, forcing Mike to hold the live crabs in his mouth, until the cry for "action", before releasing them. At one point he had to crush one with his teeth, as it gave him quite a bit of grief. Brotherly love immortalized.
Trivia: William Shatner's contract for Star Trek IV stipulated that he would only be in that movie if he could direct Star Trek V.
Trivia: Much like the set of War of the Worlds, the set of this crash was so realistic, that airline pilots near Toronto were calling in a downed aircraft as they flew near it, unaware that it was staged for the filming of this movie.
Trivia: The shots of the French army are from the 1956 film War and Peace.
Trivia: Gromit was originally supposed to be a cat, but it was decided that a dog was easier to sculpt from plasticine.
Trivia: In one version of the script, Martin finds another videotape of his father Seth. This tape would show Seth (who is in his part-fly form) explaining the "cure". This scene would have required Jeff Goldblum to be in make-up for five hours, and he didn't want to go through that, so he dropped out, and the scene was cut from the script.
Trivia: The film is also widely known as "The McPherson Tape." However, this was never the official title, and is seemingly based on a misconception since the film was often circulated without the title attached in the 90s. Regardless, this incorrect title became so well-known that the film's 2020 Blu-Ray by American Genre Film Archive (AGFA) contains a double-sided cover... one with the correct title "U.F.O. Abduction," and the other with the misnomer title "The McPherson Tape."
Trivia: In the open-matte print, right after the credits, the support beams of the movie lot walls are visible, painted in blue to simulate the sky. In the theatrical version and the current Disney+ streaming movie's original aspect ratio (bottom picture), one can still see the beams for a split second after the postman puts the letter in the mailbox (though there's no way here to identify them as lot walls).