The Birthday Box by Leslie Patricelli.
Take one look at the cover of the book, and you can get the sense of exactly how this book reads. It is a friendly, silly, imaginative book about a toddler who receives a box for his birthday. When he unwraps the paper, he is thrilled to find a box that has a stuffed dog inside it. He names the dog Oscar and they immediately set off on adventures based on the box.
My favorite part of the book is the ending where the thrill of having a cardboard box is not broken, but sustained. Perfect. I also liked the way that the real present of the stuffed dog is incorporated into the child’s play, but just isn’t the center of it. The illustrations are cartoony and friendly, perfect for toddlers.
Recommended for toddlers, but make sure to have a large cardboard box on hand in case it inspires them! This book will work for a group of toddlers as well, because it combines two fascinations: boxes and birthdays.