Monkey and Cake
Monkey and Cake volume 1
Orchard Books, an imprint of Scholastic Incorporated
Monkey has a big box, which he tells Cake has a cat inside, but only when the box is closed; Cake suggest that maybe it is a dinosaur instead, and the two friends puzzle over how they can solve the problem of finding out what is in the box, if it is always empty when opened.
Monkey and Cake volume 2
Monkey and Cake are normally good friends, but today Cake is building a no-Monkey fort--until Monkey teaches him a lesson about being alone and he realizes that forts (and other things) are much better when they are shared.