I Spy

I Spy is a children's book series with text written by Jean Marzollo, and photographs by Walter Wick, which was published by Scholastic Press. Each page contains a photo with objects in it, and the riddles (written in dactylic tetrameter rhyme) accompanying the photo state which objects have to be found. Although the first I Spy book contains unrelated pages of still life pictures, subsequent books are more thematic. Several video games based on the I Spy books are available for Windows PC, Nintendo DS, Wii, iOS, Leapster, and Game Boy Advance, including I Spy Spooky Mansion, I Spy Treasure Hunt, and I Spy Fantasy. These served as early examples of an increasingly popular hidden object game genre. I Spy merchandise has been sold in at least 31 countries worldwide.