ISBN 1887942262 - The Kindergarten level Hooked on Phonics books are fantastic, as a set. Since they're meant to be used to teach kids to read, and since they're in a certain order for a reason, get them all!
Pig Wig, Cat, Rat and Rag play tag.
The sentences in this book are very, very subtly more difficult than the previous books. For the continuity factor, introducing characters in the earliest books, then focusing on them as the main characters after that, author/illustrator Barney Saltzberg wins serious respect from me. Not since Dick and Jane have I seen a series like this for beginning readers. The illustrations, very much like coloring book pages, don't impress me at all, however.
I highly recommend the entire Hooked on Phonics series. My son is only four and is already starting to read and has mastered the first 5 Hooked on Phonics books. It makes teaching your child to read dummy proof!