Who are the Yule Lads?

From the Iceland Review:

Thirteen days before Christmas the first Icelandic yule lad sneaks into homes in the dead of the night to steal candles, skyr or slam doors – and leave presents behind in the shoes of well-behaved children.
“Who will it be tonight?” kids debate: Stiff-Legs, Gully Gawk, Shorty, Ladle Licker, Pot Scraper, Bowl Licker, Door Slammer, Skyr Gobbler, Sausage Snatcher, Window Peeper, Sniffer, Meat Hook or Candle Beggar?
When I was a kid, Door Slammer was my favorite. When he was in town I felt that I had an excuse to slam doors as much as I liked. Once I thought Door Slammer had actually paid me a visit when a door slammed so hard that the whole house rattled and I jumped out of my seat… But then my father appeared with a mysterious grin on his face.
He used to read me 19th century poems about the 13 yule lads, their horrible mother Grýla and the dreaded Christmas cat. And because I anticipated their arrival with a shoe in my windowsill – preferably a large one to get bigger presents, like my father’s boot, but unfortunately I was told to use my own shoe – I behaved exceptionally well (which was very difficult) throughout December. Occasionally, though, I woke up to find a potato in my shoe.
I’m a real child of Christmas. I have always loved Christmas preparations; making my own Christmas decorations and Christmas cards, shopping for presents, baking cookies (I have already opened a Christmas bakery in my kitchen this year), putting up Christmas lights, making Christmas bread with my family and decorating the tree.
Best of all was the anticipation which grew with each day from 1 December until Christmas, reaching a high the night before Christmas Eve when I couldn’t sleep at all at the thought of all the wonderful presents waiting for me under the tree. The days before Christmas were bearable only because of the yule lads.
My world fell apart when I was seven when the one-year-older and wiser girl next door told me: “The yule lads don’t exist; our parents sneak into our bedrooms and put presents in our shoes.”
The thirteen yule lads have disturbed the sleep of Icelandic children for centuries. At first children couldn’t sleep because they were scared to death by the yule lads, now children can’t sleep because they look forward to the gift protruding from their shoes in the morning. Some children stay awake to disprove the yule lads’ existence and catch their parents red-handed.
In the old days, the yule lads were vicious trolls – according to some tales they were over 50 in total – who lived in the mountains like outlaws, but came down before Christmas to steal Christmas food rations and torment people with their pranks. Their mother and father also came to town to snatch naughty children and eat them. The monster of a family cat had an appetite for children who didn't get new clothes before Christmas.
The stories of the yule lads evolved through the ages, and by 1746 they became so bloody that the Danes, who ruled over Iceland at that time, issued a law banning stories used for scaring children into good behavior.
But the legend lived on and it differed from county to county. In a poem from the 19th century by Jóhannes úr Kötlum the number of the yule lads was established as 13 and these are the yule lads we know today. Their names come from a collection of folktales published in 1862 by Jón Árnason.
Gradually, the yule lads’ reputation improved, and by 1930 it had been given an extreme make-over. Probably under the influence of the foreign custom of St. Nicholas, brought home by Icelandic seamen, the yule lads begun giving presents to well-behaved children.
Since 1970 every child in Iceland puts its shoe in the window thirteen nights before Christmas to wake up to a daily surprise from the yule lads. The last brother arrives on 24 December and then, one by one, they start leaving for the mountains again. The last yule lad leaves on 6 January, the last day of Christmas.
In recent years the yule lads’ appearance has been influenced by Santa Claus. Nowadays the thirteen brothers often dress in red and white instead of wearing traditional wool and lambskin clothing in earthy colors. But this year, the original yule lads are back in fashion.[1]