1.In The Muppet Christmas Carol, Michael Caine insisted that the only way he'd play Scrooge was if he pretended like the Muppets were real people and that he was acting in the Royal Shakespeare Company.
2.In Elf, the "Baby It's Cold Outside" shower scene wasn't actually in the original script. Director Jon Favreau learned that Zooey Deschanel was a good singer while filming, so he added it in.
3.In Die Hard, Bruce Willis's role was actually offered to 73-year-old Frank Sinatra first. Sinatra was contractually obligated to get first dibs because he starred in the film's prequel in 1968.
4.In Jingle Jangle, the musical actually featured three different stars of Dreamgirls from the last five decades: Phylicia Rashad, Anika Noni Rose, and Marisha Wallace.
5.In The Santa Clause 2, Tim Allen had to stay in character around the child actors, even when cameras weren't rolling, because a lot of the kids believed he was the real Santa.
6.In Happiest Season, cowriter and director Clea DuVall based the premise of this movie on her own life because she loves Christmas films but had never seen her own experience as a lesbian reflected in them.
7.In Home Alone, the prop department originally created a fake tarantula to put on Daniel Stern's face, but director Chris Columbus insisted on using a real one (and its name was Barry!).
8.In Love Actually, they originally shot four additional storylines, one of which included the school's headmistress and her partner, who was battling a terminal illness.
Here's the DVD commentary and scene:
9.In It's a Wonderful Life, writer-director Frank Capra helped create a new type of artificial snow because the then-current movie method (using cornflakes that were painted white) was too noisy when the actors had to walk in scenes.
10.In A Christmas Story, Flick's tongue was actually suctioned by a hidden vacuum to give the illusion that it was frozen to the pole.
11.In Jingle all the Way, the whole premise of the movie was actually inspired by the Cabbage Patch Kids craze from the Christmas season of 1983, when parents were literally fighting at stores to get their children these dolls.
12.In Last Holiday, the deluxe hotel that Queen Latifah's character stayed at, called Grandhotel Pupp, is actually a real hotel in the Czech Republic.
13.In Miracle on 34th Street, the parade scenes were shot on location during the 1946 Macy's Thanksgiving Day Parade, which meant they only had one morning to film all the scenes they needed for the movie's opening.
14.In How the Grinch Stole Christmas, both Eddie Murphy and Jack Nicholson were originally considered for the role of the Grinch, but it ultimately went to Jim Carrey.
15.In Home Alone 2: Lost in New York, Donald Trump would only give the production team a permit to film in the Plaza Hotel (which he owned at the time) if they wrote him into the movie.
16.In It's a Wonderful Life, the entire Christmas movie was actually shot in the summer of 1946, and it occasionally got so hot that production literally had to be shut down for a few days.
17.In Elf, Will Ferrell, Jon Favreau, and a cameraman ran through New York on the final day of shooting and interacted with people on the street to film the "Buddy discovers New York" montage. So, no, those people weren't paid extras — they were just random New Yorkers.
You can watch the full scene here:
18.In Home Alone, that picture of Buzz's girlfriend was actually a picture of the art director's son wearing a wig.
19.And in Love Actually, Emma Thompson actually wore a fat suit underneath her clothes throughout the entire production.