Black Christmas (1974)

We're going old school today! While the original Black Christmas was not the first movie involving what we today would refer to as a "slasher" killer (the original The Texas Chain Saw Massacre came out the same year), it helped popularize the horror subgenre. But is this film really about Christmas? Absolutely not. It would've been just as easy to set it during spring break. But it happens right before Christmas, so here we are, talking about it in December. Merry technicality!