Love Elf On The Shelf T-ShirtElf On The Shelf is a picture book for children, which comes in a keepsake box that features a hardbound picture book and a small scout elf, who is placed on a shelf to watch over events. The book tells a Christmas themed story, written in rhyme, that explains how Santa Claus knows who is naughty and nice. It describes elves visiting children from Thanksgiving to Christmas Eve, after which they return to the North Pole until the next holiday season.