Grýla was not directly linked to Christmas until the 17th century. By that time she had become the mother of the Yule Lads. Terry Gunnell hypothesizes that the medieval custom of dressing as Grýla may be related to other visiting traditions such as Julebukk or the Yule Goat and that her name may mean “threat” or “threatening”.
She has the ability to detect children who are misbehaving year-round. During Christmas time, she comes from the mountains to search nearby towns for her meal. She leaves her cave and hunts for the children. She devours children as her favorite snack. Her favorite dish is a stew of naughty kids for which she has an insatiable appetite. According to legend, there is never a shortage of food for Gryla.