In Toy Story, Buzz Lightyear's original name was Lunar Larry. After a lot of back and forth, it was eventually changed to honour real-life astronaut Buzz Aldrin.
In the scene from Poltergeist where JoBeth Williams swims through a pool of bones and skulls, she wasn't diving with props. They were real dead bodies.
On the set of Romeo and Juliet. One of the movie's hair and makeup artists was kidnapped by gang members and held for ransom. He was returned by being thrown out of a moving car which caused him to break a leg.
Daniel Radcliffe was supposed to wear green eye contacts throughout the Harry Potter movies in keeping with the description of the character in the book. However, he found them so excruciatingly uncomfortable that they just decided Harry would have blue eyes instead.
Paul Bateson, who played an X-Ray technician in The Exorcist, was a convicted murderer who dismembered and killed a series of gay men in the 1970s.
Gene Kelly performed the title number in Singin' In The Rain with a fever of 103°F.
The sound of the velociraptors in Jurassic Park is actually a recording of two tortoises having sex on a loop.
The man at the end of Titanic drinking from a flask was based on a real passenger who survived in the Atlantic as a direct result of his blood alcohol level.
After an astrophysicist contacted James Cameron to tell him that the constellation of stars Rose looks up at while on the door in the ocean was wrong, he re-edited the scene for the 10th anniversary director's cut.
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