The Jungle Book

A great book. Not only the well known story of Mowgli, but a bunch of other ones too, and in each, the author does a masterful job of anthropomorphizing jungle animals, not as a cutesy caricature but as multi-faceted being, understanding their place in society, following their needs, desires, and a deeper honor code by which all animals of the jungle must abide.

No wonder this is a classic.