You'd better watch out, you'd better not cry – or you may get an unwanted visit from Krampus, the Christmas demon.

All around the world at Christmastime, children gleefully await the arrival of Santa Claus and a windfall of presents under the Christmas tree. Of course, that's all well and good if you've been nice – but what if you were a naughty boy or girl this year? In the regions of Alpine Austria and southern Bavaria, that adds up to a terrifying visit from Krampus, the half-goat, half-demon sidekick to Saint Nick whose mission is to punish the misbehaved.

Krampus – whose name is derived from the Old High German word krampen, which means "claw" – is said to be the son of Hel, the god of the underworld in Norse mythology. Emerging from European pagan traditions, Krampus is a figure you'd be right to be scared of – no matter your age. With his flaming-coal eyes, matted fur, cloven hooves, snarled horns, long pointed tongue and jagged fangs, this "Evil Santa" appears on Krampusnacht, occurring the night before the Feast of Saint Nicholas.

Looks aren't everything, of course.

Krampus carries a basket or a sack, a set of shackles, a whip and a bundle of branches for the purpose of swatting naughty children. Sometimes alongside Saint Nick and sometimes solo, Krampus visits the local homes and businesses, handing out lumps of coal and birch bundles – a sobering reminder of the dire results of being naughty.

What's that ominous basket for, you may ask? Why, it's for carrying the bad children back to the pits of hell for all manner of torture. Adults, you'd be right to be scared out of your wits, too – in those particularly egregious cases of naughtiness, parent-napping is included in his repertoire as well.

Krampus has recently spread his reach around the world. He's a frightening reminder to children everywhere that they'd better be on their best behaviour, no matter the season – because you never know when he's going to show up on your doorstep.

So which list are you on this year? Better check it twice…