Waldo's Key first appeared in The Ultimate Fun Book. Waldo lost his key on every scene and the reader had to find it in each one. It would later appear in following books and be reworked into the special editions. No one, not even Waldo himself, knows what the key unlocks.
Books featuring Waldo's key[]
- The Ultimate Fun Book!
- The Magnificent Poster Book!
- Where's Waldo in Hollywood
- The Where's Waldo? classics' "Special" editions.
- The Wonder Book
- The Great Picture Hunt!
- The Incredible Paper Chase