The Elf on the Shelf: A Christmas Tradition is a 2004 children's picture book, written by Carol Aebersold and daughter Chanda Bell and illustrated by Coë Steinwart. The book tells a Christmas-themed story, written in rhyme, that explains how Santa Claus knows who is naughty and who is nice. It describes elves visiting children between Thanksgiving and Christmas Eve, after which they return to the North Pole until the next holiday season. The Elf on the Shelf comes in a keepsake box that features a hardbound picture book and a small soft toy in the form of a pixie scout elf.