J.K. Rowling has written two limited-edition ''Harry Potter'' companion books -- each under a ''Potter''ish pen name and each benefitting Comic Relief U.K. One, ''Fantastic Beasts & Where to Find Them,'' is a keeper. The other, Quidditch Through the Ages (a purported history of the high-flying sport popular in Potter's enchanted world), suffers from a malady common to most sports manuals: it's kinda boring. But it comes alive with its guide to the world's great teams (long-suffering Chicago Cubs fans will find the Chudley Cannons painfully familiar) and its explanation for why Quidditch hasn't caught on in the U.S. -- apparently, we prefer the football-like Quodpot.