Gryla

Gryla is an ogress that appears in the Season 2 episode "Chapter 10: The Yule Lads", as well as the tie-in novel "Hilda and the Time Worm".

Appearance
Gryla is a gigantic, hunchbacked ogress, with a body covered in thick fur. She has sharp spines on her back and antlers on top of her head. Her face is covered by a mask to protect her ancient skin against the moonlight. The mask is broken around her left eye. She is clothes in rags.

Behaviour
According to legend, Gryla has the ability to sniff out naughty children, and feeds on them by making a stew out of them. She sleeps most of the year, but awakens around the time of the Trolberg Winter Festival to feed.

Biography
Gryla is at least several centuries old. Very few have ever seen her. At some point in the past, 13 of the children she abducted came to work for her as the Yule Lads. She keeps them in line with the threat to eat them if they don't find her any other naughty children to eat.

In "Chapter 10: The Yule Lads"/"Hilda and the Time Worm", she is seen slowly making her way to Trolberg. Along the way, she frightens even Baba and Baba's mom. Somehow, she manages to get into the city unnoticed. By the time she gets there, the Yule Lads have been convinced by Hilda to give her the Sparrow Scouts' vegetable broth as a substitute for humans. Fortunately, Gryla accepts the alternative and leaves again.

Trivia

 * A difference between the novelization and the animated series is that, in the novel, Hilda twice spots Gryla as she is on her way to Trolberg; once while riding in the zeppelin of the Safey Patrol, and once after she and the Keeper of the Bell have sabotaged Erik Ahlberg's mechanical bellringers. In the series, Hilda doesn't get to see Gryla until she actually arrives in Trolberg.
 * Gryla is based on a gigantess from Icelandic folklore. The oldest poems in which she appears describe her as a parasitic beggar who walks around asking parents to give her their disobedient children. Her plans can be thwarted by giving her food or by chasing her away. In the mythology, she has a husband named Leppaludi, and the Yule Lads are their sons.