This was a nice little book about a gorilla, protecting animals, friendship, so many things. It's based on a real gorilla who was named Ivan and died just a few months ago in a zoo. It's worth reading about the real Ivan (there's a bit in the book, but much more online) too.
While the basic outline of the story is true, the plot itself isn't, which is obvious if you read it. It's really just simple. But nice.