The "Elf on the Shelf" is a popular Christmas tradition that originated in 2005. The story goes that a scout elf is sent by Santa to watch over children and report their behavior to Santa. The scout elf then hides in a different place in the house each day, creating a fun and magical game for the children to find them. It is believed that the scout elf brings Christmas joy and magic into the home, creating a special bond between the children and Santa.