The Elf on the Shelf is a beloved holiday tradition that began in 2005 when author and publisher Carol Aebersold and her daughter Chanda Bell created a special Christmas elf that would observe the behavior of children to determine whether they were being naughty or nice. The elf became so popular that it has since spawned a whole franchise of books, toys, and merchandise. The first Elf on the Shelf storybook, "An Elf's Story," was published in 2005, and the tradition continues to this day, with millions of families participating in the fun.