The Elf on the Shelf is a popular Christmas tradition that started in 2005. The story follows an elf who is sent from Santa's workshop to report back to Santa on whether children have been good or naughty. The elf hides in a different place each day, watching the children's behavior and reporting back to Santa. As the story goes, if the elf is not treated well, he will not move around or have fun with the children. If the elf is treated well, he will play games with the children and even create magical scenes around the house.