what is an elf on a shelf

The Elf on the Shelf is a toy that Santa sends to families as a holiday tradition. The elf arrives just before Christmas and is responsible for monitoring children's behavior, reporting back to Santa about who has been naughty and who has been nice. The elf is said to have magical powers that allow it to move around the house and surprise the children with its antics. The elf's job is to remind the children to behave and make good choices throughout the holiday season.