The Yule Lads are Icelandic folklore’s twisted idea of the Santa Claus we know and love in many western countries. Rather than being jolly, fat and with a sack full of presents, these thirteen half-trolls are grotesque, deformed, and indiscriminate in who they target over the festive season.

Stekkjarstaur, Sheep-Cote Clod, has already made his way around the country, riling up ewes and rams. But Icelandic children still huddle together, this time in fear of his brother who just left his home in the mountains. Giljagaur, or Gully Gawk, is as detestable as his other twelve siblings, but his method of cause mischief and fear is unique.

Giljagaur hides in the gullies around a house, waiting until its residents have fallen asleep before making his way into the cowshed. Here, he will steal any milk available, taking it straight from the udders if he must. He is thus robbing families of the key ingredient in the sauces and Skyr meant to be enjoyed over the festive season.

Giljagaur will make his way from home to home for thirteen days, finally returning to his cave in Dimmuborgir on Boxing Day. Any milk he hasn’t guzzled down he will no doubt hand to his mother, the terrifying giantess Grýla, to help her flavour the naughty children she has captured this Christmas and plans to devour.

The first two Yule Lads cause particular trouble for those who live out in the countryside, hassling livestock and upsetting the livelihoods of the nation’s farmers. City kids, however, know they are free from fear for just this night; but for the next eleven days, the brothers of Stekkjarstaur and Giljagaur will be coming for them too…