The Elf on the Shelf is a beloved tradition that began in the 1970s when a woman named Carol Aebersold and her daughters wrote a book called "The Elf on the Shelf: A Christmas Tradition." The story tells the tale of a mischievous elf who watches children's behavior and reports back to Santa Claus each night. Since its release, the concept of the Elf on the Shelf has become a popular holiday tradition, with many families adopting their own elf and using it to add a magical touch to their Christmas celebrations.