For Icelandic children, the magic of Christmas starts 13 nights before Christmas day. They place a shoe on the windowsill hoping they have been well behaved enough that year to receive candy from one of the 13 Yule Lads. If not, their shoe may be filled with rotten potatoes instead! Although, some stories claim that these mischievous creatures eat bad children.
The Yule Lads are a group of pranksters by the names of Sheep-Cote Clod, Gully Gawk, Stubby, Spoon Licker, Pot Licker, Bowl Licker, Door Slammer, Skyr Gobbler, Sausage Swiper, Window Peeper, Door Sniffer, Meat Hook, and Candle Beggar. While just about all of their names are as self-explanatory as it gets and does not need further explanation, there are a few confusing ones. Sheep-Cote Clod tries to milk and drink from sheep, Gully Gawk steals some foam from a bucket of cows milk, Stubby steals food from frying pans and Skyr Gobbler will eat your yogurt.
Tales of the Yule Lads can be found as far back as the 17th century in the Poem of Gryla. Gryla was a giantess who senses when children are bad no matter the year and snatches them up in her sack to eat. She is the mother of the Yule Lads.
There was also a Yule Cat who was extremely large and also ate people. He belonged to Gryla and her menacing sons. For whatever reason, it is said he only ate humans who did not wear new clothes on Christmas Eve. This was used to scare farm hands to hurry and process wool in the fall before Christmas. A less horrifying version on the Yule Cat says that he just eats the foods of those with old clothes on.