Gryla is an ancient, very dangerous witch.
During a famine, Gryla and another witch from her coven made a pact to eat their own children to survive. They cooked and devoured Gryla's son first, her only child, and then the other witch broke their pact. Devastated, Gryla's spent the last thousand years trying to replace her lost child. At some point, she was abandoned by her husband. She's looking for children, particularly children to add to her "family"; they're known as the Yule Lads, for the mischief they cause every midwinter.
Gryla has long, wavy blonde hair and crimson lips. Her clothing is rough, and she looks every bit the part of a primal witch living in the wild.
Gryla loves and genuinely cares about children. She continually tries to get children, particularly orphans, to join her "family", although she has been known to let children go if their biological families are still alive and still care about them. Gryla detests people hurting children. She also hates men after her husband abandoned her, although this dislike does not seem to extend to male children.