Every year in early December, children in Austria get ready for St. Nicholas to visit them. If they’ve been good, he’ll reward them with presents and treats. But if they’ve been bad, they’ll get a lot more than a lump of coal—they’ll have to face Krampus.
Who’s Krampus, you ask? He’s the half-man, half-goat who comes around every year to chase naughty children and maybe even drag them to hell. European versions of St. Nicholas have long had scary counterparts like Belsnickel and Knecht Ruprecht, who dole out punishment. Krampus is one such character who comes from folklore in Austria’s Alpine region, where he’s been frightening children and amusing adults for hundreds of years. -History
Krampus and Krampus Nacht originated in Germany centuries ago. His name derives from the word “krampen”, which means claw. He is considered to be a cruel counterpart to the kind St Nicholas character. While St Nicholas would reward children for being good, Krampus would punish children for being bad. Legend says he is the son of Hel, the Norse god of the underworld, and he may have originated as part of a winter solstice pagan ritual. The Catholic church attempted to ban Krampus celebrations because he resembled the devil. -The Standard

In Alpine Austria and some parts of Germany, this day was known as Krampusnacht, or “Krampus night,” when adults might dress up as Krampus to frighten children at their homes.
Children might have also seen Krampus running through the street during a Krampuslauf—literally, a “Krampus run.” If Krampusnacht was a way to scare kids into behaving themselves, the Krampuslauf, which isn’t tied to a specific day, was a way for grown men to blow off steam while probably still scaring kids. Austrian men would get drunk and run through the streets dressed as the fearsome creature. Like Krampusnacht, the Krampuslauf tradition continues to the present day.
The introduction of mass visual media couldn’t help but sweep the charismatic Krampus up in its wave. When the postcard industry experienced a boom in Germany and Austria in the 1890s, it opened the way for Krampuskarten.
These holiday cards weren’t meant to make you feel warm and fuzzy. Ones marked “Gruss vom Krampus” (“Greetings from Krampus”) showed Krampus stuffing a distressed child into his satchel or preparing to hit one with his bundle of birch sticks. Many of these postcards depicted Krampus going after children with his sticks, leading them away in chains, or carrying them off in his bag.
For over a century, most Americans probably never saw a Krampus card or knew who Krampus was. That changed in 2004 when art director and graphic designer Monte Beauchamp published a book of Krampus cards and helped organize an art show inspired by the cards.
Whether or not Beauchamp is primarily responsible for introducing Krampus cards to the U.S., Krampus has since become a sort of ironic icon in America. Etsy has a whole section of items inspired by classic Krampus cards. And if you don’t have time to send cards, you can buy an ugly Krampus sweater to wear to your local Krampus party or Krampuslauf. Krampus’ popularity in the U.S. arguably peaked with the 2015 feature film Krampus, which shouldn’t be confused with the many other low-budget Krampus movies.
Although Krampus is relatively new to the U.S., this alpine legend is the original bad Santa. -History
Information from Alternative Press and Britannica
Krampus isn't the only mythical beast that could come after the naughty boys and girls. There is also the Icelandic Jólakötturinn, also known as the Yule Cat, who comes after the children who are ungrateful for the new clothes they receive for Yule/Christmas and refuse to wear them.
"Jóhannes úr Kötlum, an Icelandic poet, wrote about the Yule Cat in his book, Jólin koma (Christmas is Coming), published in 1932.
Kötlum's poem tells the tale of a cat that's "very large" with glowing eyes. It roams the countryside, going from house to house looking for children who aren't wearing the new clothes they got for Christmas, according to the poem.
Memes of the Yule Cat have been making their way around social media; some are meant to be spooky, while others are a blend of fascination and satire." -NPR
Other variations of the Yule Cat come from Icelandic traditions. "According to Icelandic tradition, anyone who finished their chores before Christmas would get new clothes as a reward. Meanwhile, lazy children who didn’t get their work done would have to face the Jólakötturinn. It towers above the tallest houses. As it prowls about Iceland on Christmas night, the Yule Cat peers in through the windows to see what kids have gotten for presents. If new clothes are among their new possessions, the big cat will move along. But if a child was too lazy to earn their new socks, the Jólakötturinn will eat their dinner, before moving on to the main course: the child themself." -Smithsonian
"Presumably, the threat of being eaten by the Jólakötturinn is also meant to inspire generosity in children who don’t have to fret about the Yule Cat, as giving clothes to the less fortunate would grant them protection from the monstrous feline. But the giant beast isn’t even the only human-eating Christmas monster that Icelanders have the misfortune of having to face every year. There’s also the Jólakötturinn’s owners: the trolls Grýla, Leppalúði, and their 13 children, who are collectively known as the “Yule Lads.”

