- They put rewards or punishments into shoes placed by children in window sills during the last thirteen nights before Christmas Eve. Every night, one Yuletide lad visits each child, leaving gifts or rotting potatoes, depending on the child’s behaviour throughout the year.
- The Yuletide-lads were originally portrayed as being mischievous, or even criminal, pranksters who would steal from, or in other way harass the population (at the time mostly rural farmers). They all had descriptive names that conveyed their modus operandi.
- Giljagaur (Gully Gawk) - Hides in gullies, waiting for an opportunity to steal milk.
- Þvörusleikir (Spoon-Licker)
- Hurðaskellir (Door-Slammer) - Likes to slam doors, especially during the night.