Elf on the shelf is a Christmas tradition that has been around since 2005. The tradition involves a small elf doll that comes to life and watches over children during the holiday season, reporting back to Santa about their behavior. The elf usually appears on the first day of December and leaves on Christmas Eve, providing a magical and fun way for children to countdown to Christmas. The exact date when Elf on the Shelf will return is still a mystery, but it's likely to be sometime in late November or early December.