If you’ve been performing your unwritten duty as a horror fan this month, you’ve already watched a handful of fan-favorite holiday horror classics, such as Black Christmas, Silent Night, Deadly Night and Christmas Evil. It is indeed the most wonderful time of the year, and us fans have got no shortage of awesome movies to keep us warm throughout the holiday season.

Think you know everything there is to know about the best films that fall into that holiday horror sub-genre? Well, here are 10 fun facts that you just might not know!

1) Though 1984’s Silent Night, Deadly Night is considered the ultimate killer Santa horror movie, it’s far from the first one to depict the loveable icon as a sadistic slasher. That honor belongs to 1972’s Tales from the Crypt, a British anthology film that featured a segment titled ‘And All Through the House.’ Based on a story featured in the Vault of Horror comic series, the tale is about a woman who kills her husband and is then terrorized by a madman wearing a Santa suit.

Over a decade later, HBO’s Tales from the Crypt television series brought the same story to life. ‘And All Through the House’ was the second episode of the show’s first season.

2) In 1980, Last House on the Left star David Hess made his directorial debut with To All a Goodnight, a holiday horror effort that is noteworthy for being the first feature length film about a killer Santa Claus. It’s your typical slasher fare about sorority girls being killed off on Christmas break, and it’s one of only a small handful of movies to put a female killer inside the iconic red suit.

To All a Goodnight went on to be the only film directed by Hess, who passed away in 2011.

3) In Silent Night, Deadly Night, there’s a scene wherein the cops spot a man dressed as Santa entering a bedroom window, and though they think he’s the killer, he turns out to be a dad surprising his daughter. The Santa in that scene was played by stuntman Don Shanks, who is most known for portraying Michael Myers in Halloween 5. Shanks was a stunt coordinator on the film, and also served the same duty for the sequel.

4) One of the most iconic things about Silent Night, Deadly Night is the poster art, which shows an axe-wielding Santa going down a chimney. The memorable photograph was taken by artist Burt Kleeger, who also took several other shots that were left on the cutting room floor. Above are two of the unused concept photos, which Kleeger shared with Halloween Love earlier this year – the first time they were ever released to the public.

5) You of course can’t talk holiday horror without mentioning 1974’s Black Christmas, which is considered by many to be the highest point of the sub-genre. At one point in time, director Bob Clark had brainstormed a sequel to the slasher film, which would take place on Halloween and see the killer from the first film being released from a mental institution. A few years after Clark told the idea to John Carpenter, he made Halloween, which featured much the same plot.

So yes. In some strange way, Halloween is kinda/sorta a sequel to Black Christmas!

6) If you’ve seen it, you know that the 1987 sequel to Silent Night, Deadly Night is comprised mostly of recycled footage from the first film, and believe it or not the original plan was that no new footage was going to be shot for it. After Silent Night, Deadly Night was pulled from theaters amidst all the parental outrage, TriStar decided to recut the footage and turn it into a different film, which they could then put back out there.

Per the suggestion of hired director Lee Harry, the studio decided to allow him to shoot additional footage, which is how Billy’s brother Ricky came into the picture. “We figured the least-heinous way to make use of the original footage was as flashbacks with little brother Ricky as the link, even though he’s WAY too young to remember most of it,” Harry told FEARNET.

7) One of the more interesting holiday horror films is 1980’s Christmas Evil, which again predated Silent Night, Deadly Night by a handful of years. The killer Santa in that film was portrayed by actor Brandon Maggart, who is in real-life the father of singer Fiona Apple!

If you’re a fan of Christmas Evil, you might want read the iHorror interview with Brandon Maggart.

8) When Silent Night, Deadly Night came out, veteran actor Mickey Rooney famously condemned the film in a scathing letter written to the producers, calling them scum and saying that they should be run out of town for turning Santa into a killer. Less than a decade later, Rooney had a complete change of heart, starring as the killer in Silent Night, Deadly Night 5: The Toy Maker.

And yes. In one scene, Rooney dons a Santa suit and does some killing. Oh, the irony.

9) Black Christmas got the remake treatment in 2006 with a much gorier slasher film, simply titled Black X-Mas. In the sorority house, those with a keen eye will spot the iconic leg lamp from holiday classic A Christmas Story. This was a little homage to original Black Christmas director Bob Clark, who oddly enough also directed A Christmas Story!

10) The most beloved holiday horror movie of them all is Gremlins, which is celebrating its 30th birthday this year. In the original script, the film wasn’t quite so family-friendly as the finished product turned out to be, featuring scenes of a woman being decapitated and Barney the dog being killed and eaten. The science teacher was also originally going to die, after having dozens of needles stuck into his face.

Ultimately, both director Joe Dante and studio Warner Bros. decided to make the film more appealing to a family audience, forcing them to rewrite the script.