Krampus, a half-goat, half-demon of centuries-old Austrian lore who's known for beating naughty people around Christmastime, is having a moment.

Krampus parties and parades are happening across the United States, and the figure has his own American comic book series. Last week, Austrian-German actor Christoph Waltz told Jimmy Fallon about Krampus on the Tonight Show, with help from a Krampus doll.

"St. Nicholas comes with praise and presents and wisdom," Waltz said. "Krampus [comes] with a stick, a bag ... If you weren't good, you get stuck in the bag and hit and shipped off.

"You have to remember Sigmund Freud was Austrian," Waltz deadpanned.

Who Is Krampus?

Some Krampus fans say it's the commercialization of Christmas and the lure of a less cheery holiday character—Krampus has horns, dark hair, and fangs—that drove them to celebrate the beast.

"It's a way to celebrate the more unexplored side of the holidays," said Erica Saunders, managing director and collections manager of the Morbid Anatomy Museum in Brooklyn, New York. The museum has thrown an annual Krampus costume party for the past few years.

"We're not devil worshipers," said Mark Maynard, who has helped organize an annual Krampus ball in Ypsilanti, Michigan, since 2011. "We're just having a party."

Origins of Krampus

Krampus, whose name is derived from the German word krampen, which means claw, is said to be the son of Hel, who rules the realm of the dead in Norse mythology. Krampus also shares characteristics with demonic creatures in Greek mythology, including satyrs and fauns.

The legend is part of a centuries-old Christmas tradition in Austria and southern Germany, where Christmas celebrations begin in early December.

"It's really a pagan character which gets added onto Christmas, and stays in the Catholic countries," said Peter Jelavich, professor of history at Johns Hopkins University, in Baltimore.

Krampus is a counterpart to kindly St. Nicholas, who rewards children with sweets. Krampus, in contrast, swats "wicked" children with birch sticks and takes them to his lair.

According to folklore, Krampus shows up the night before December 6, known as Krampusnacht, or Krampus Night. December 6 is Nikolaustag, or St. Nicholas Day, when German children look outside their door to see if the shoe or boot they'd left out the night before contains presents (a reward for good behavior) or a rod or twigs (for bad behavior).

View Images Participants gather before dressing as Krampus in Neustift im Stubaital. More than 200 Krampuses participated in the first annual event last year. Photograph by Sean Gallup, Getty

European Comeback

For years, Krampus was suppressed by the Catholic Church, which forbade raucous celebrations in the demon's name. During World War II, Europe's fascists deplored Krampus as a creation of the Social Democrats.

But the demon is making a comeback in his homeland. Austrian retailers are attempting to soften Krampus's persona by selling chocolates, figurines, and collectible horns. National Geographic has published a book in German about the Christmas beast.

In Austria, Germany, Hungary, Slovenia, and the Czech Republic, many men celebrate Krampusnacht by getting drunk, dressing as devils, and taking over the streets in a kind of Krampus run, chasing pedestrians through the streets.

Mythology experts say that such antics present a way for humans to get in touch with their animalistic sides. (Read about European men reviving pagan traditions in National Geographic magazine.)