Santa is feeling old, and being in the business of Christmas for centuries is . . . well, it isn't all milk and cookies. In hopes of regaining some of his pep, Santa asks the spirit of Christmas to give him something for a change: skim off a couple of years and make him younger. But Christmas magic is powerful, and Santa gets more than he wished for. Instead of a fresh new outlook and boundless energy, he needs diapers and a...