Christmas time is Marcus Eriksonupon us, and though children loathe getting new clothes for gifts, they best put on that new itchy sweater or slide on those unwanted socks. Or else risk being eaten alive by a giant cat, at least according to Icelandic folklore.

That's right. A child's worst nightmare — new clothes under the tree — could only be outdone by a somehow worse nightmare, being devoured by a ferocious feline that hunts down children caught not wearing their new clothes.

The tale of Jólakötturinn, which translates to Yule Cat, is an Icelandic Christmas classic dating back to at least 1932, according to the Icelandic Folklore website, a research project managed by the University of Iceland.

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.

"I am really fascinated by other culture's holiday traditions so shoutout to my boy the Yule Cat," one meme reads. "A monstrous cat who roams Iceland eating people who aren't wearing the clothes they got for Christmas."

The Yule Cat isn't the only sinister character that comes around Christmas.

Another European folklore character is Krampus, an anti-Santa demon that kidnaps and punishes naughty kids, according to mythology.net. Munich, Germany, hosts an annual Krampus run, which attracts hundreds of participants — and more spectators — every year.