Heny Knows who Took the Cookie from the Cookie Jar

Over the holidays neighbor friends of ours (the Lewis') dropped off a large stack of children's books that their grandchildren had outgrown. In the stack of books was a pop-up book of "Who took the Cookie from the Cookie Jar?" - which has quickly become Henry's favorite. This makes sense because it combines many of his favorite things of life in one easily to handle book. The first being that it is a book - one of his favorite mediums of play and exploration. The second - it is about cookies. The third, and probably most important, is that it has "doors" (the cookie jars) that open with different animals hiding inside. This just kills Henry! And what kills me is that after reading only a couple times Henry remembers which of the six animals is hiding behind each jar!!!