This might be the season of St. Nick, but his darker, more demonic alter ego has a full schedule as well.

Krampus, a horned devil-goat from Europe known for punishing naughty kids in the run-up to Christmas, is infiltrating the US.

In October, he hit American homes with the VOD release of “A Christmas Horror Story” starring William Shatner. He followed up with “Krampus: The Reckoning” in early November and continues his un-Christian crusade this Friday with the release of “Krampus,” starring Toni Colette and Adam Scott.

The menacing creature has his origins in pre-Christian pagan traditions, evolving over the centuries to symbolize the Christian devil. His name comes from krampen, the German word for “claws,” and he’s long demonized those in Austria, southern Germany, Hungary, Slovenia and the Czech Republic.

“He’s St. Nicholas’ assistant,” explained German-Austrian actor Christoph Waltz to Jimmy Fallon on “The Tonight Show” last December. “St. Nicholas comes with praise and presents and wisdom … and Krampus comes with a stick [and] a bag, and he threatens you with — if you weren’t good, you get stuck in the bag and hit.”

Every year on Dec. 5, the day before St. Nicholas Day, European towns erupt in rowdy Krampus escapades. In Oberlienz, Austria, a group of about 70 to 80 men clad in head-to-toe sheepskin run through the town, pushing and shoving anyone who gets in their way in a kind of schnapps-fueled stampede that sometimes ends in mass injuries. A December 2013 headline from the Tiroler Tageszeitung reads: “70 Injured in Krampus Run.”

“I vividly remember a Krampus [Night] in the countryside near Salzburg,” remembers Natascha Demner, an Austrian expat living in New York City. “There were Krampuses walking around at night, wearing incredibly scary masks and furred costumes, rattling big chains and beating the children they could get their hands on with brooms . . . This is still the tradition and I will keep my kids as far away as possible from such customs.”

Others are more positive about the tradition. “Krampus embodies how at times it’s so wonderfully scary to grow up in this part of the world,” says Danica Panza, who lives in Vienna.

Indeed, kids in Austria are faced with abject terror at these festivals, where Krampus is often above the law. (For many years, the Catholic Church banned the raucous festivities.)

“The police officers disappear or have changed into plain clothes for the evening,” says Oliver Lehmann, head of stakeholder relations at Institute of Science and Technology, Austria. “Shortly before all hell breaks loose, the mayor of the village announces over the megaphone: ‘From here, you are on your own. The municipality will take no liability for any damage done. If you wish to leave, do it now, [or] else you will have to stick it out until this is over. Good night.’ ”