The world of Harry Potter is richly populated with incredible creatures, dark villains, best friends and countless mysteries. This guide is crammed with all the facts and trivia that every Harry Potter fan should know: about Muggles and Squibs; Professor Dumbledore and Aunt Petunia; and the secrets that link Harry and He Who Must Not Be Named. With the latest insights on Harry Potter and the Half-Blood Prince, this is the essential companion to all the Harry Potter books and films.