This document describes Icelandic Christmas traditions centered around the Yule Lads and the giant troll mother Gryla. It discusses each of the 13 mischievous Yule Lad brothers who arrive in the days leading up to Christmas, including what day they come, their antics like stealing food or slamming doors, and the small gifts they leave for children. It also mentions the Yule Cat that hunts children who have not received new clothes for Christmas and the role of Gryla as the mother of the Yule Lads.