Santa's Slay

On Christmas Eve in Alberta, Canada, the Mason family is bickering about their wealth and material possessions while eating Christmas dinner when Santa Claus comes down the chimney and kills them all in various graphic displays of Christmas-themed violence, such as drowning the matriarch Virginia in eggnog, using the star atop a Christmas tree as a shuriken, and stabbing the patriarch's hands to the table with silverware and force-feeding him a leg of turkey before impaling his mouth on it.
Riding on his sleigh driven by his "hell-deer", a buffalo-like beast, Santa arrives at Hell Township and decimates the locals in various holiday-themed ways. In one of his kills, Santa slaughters the occupants of a local strip club. Pastor Timmons, a crooked minister, manages to survive the massacre. Later, Santa murders the local Jewish delicatessen owner Mr. Green using his own menorah.
Meanwhile, teenager Nicholas Yuleson is living with his grandfather, a crackpot inventor who has built a bunker in their basement to survive Christmas. When Nicholas asks Grandpa why he hates Christmas, he is shown "The Book of Klaus", which reveals the origins of Santa Claus. Apparently, Santa was the result of a virgin birth produced by Satan. Christmas was "The Day of Slaying" for Santa until A.D. 1005, when an angel defeated him in a curling match and sentenced him to deliver presents on Christmas for 1,000 years. This means that Santa is free to kill again in 2005.
Upon arriving at the delicatessen, Nicholas is taken to the police station for questioning about Mr. Green's murder. He is bailed out by his love interest, Mary "Mac" Mackenzie, just before Santa arrives and kills all of the officers. Santa pursues Nicholas and Mac in a police car, but they are able to escape, thanks to a shotgun in Mac's truck. They flee to his grandpa’s bunker, with Santa still in pursuit. Nicholas and Mac manage to escape using Grandpa's snowmobile; Grandpa Yuleson is apparently killed.
The two teens hide in a local high school, hoping that Santa's powers will end once Christmas ends; but they are eventually forced to confront him in the gym. They are almost killed by Santa on a Zamboni but are saved by Grandpa, who is actually the angel who originally defeated and sentenced Santa. With Christmas over and his powers gone, Santa flees; but his "hell-deer" is shot down by Mac's father with a bazooka. Pastor Timmons is found dead in a Santa suit and is presumed to be the killer, while, in fact, the real killer Santa Claus is boarding a flight from Winnipeg to the North Pole under the name "Mr. Šatan." Nicholas notes to Mac that Santa is bound to come back, stating he's finishing what his grandfather started. He and Mac then share a kiss to pursue a relationship.
After the credits, Santa is seen looking over his Naughty List, when he looks into the camera and says "Who's Next?"