The Elf on the Shelf is a beloved tradition that began in 2005 with the release of the book "The Elf on the Shelf: A Christmas Tradition." The concept is that a magical elf is sent from the North Pole to keep an eye on children and report back to Santa Claus. Every day, the elf finds a new hiding place in the house, and children are encouraged to find the elf each morning. The elf typically arrives on the day after Thanksgiving, which is typically around the end of November.