Animal Life, which was "authenticated by the American Museum of Natural History" is the kind of coffee table/door stop/comprehensive collection that any curious kid or adult will go nuts over. It's from DK so can imagine how impressive the full color photographs and illustrations are (and there are thousands of them). But it's the unique way that the information on the animals is presented that really knocked my socks off. You have sections on all matter of anatomy, a look at how different animals move (from leaping to running, sections on vibration and echolocation, a comprehensive look at habitats ("living space"), migration, hunting, and on and on and on. From lions to praying mantis, the coverage of all manner of mammals and insects, fish and birds is awesome.
You just could not ask for a better single resource on animals and honestly, if you have a ton of animal books already (like I do) then this is just the icing on the cake. It has a steep price ($50) but consider it a life purchase. You will have this book and reference it for decades, I guarantee it.
For the new environmentally conscious 21st century, books like Animal Life are touchstones in how we live with the other creatures on the planet. There's no more pretending that we are the only ones who matter - might as well learn as much as we can about everyone else and this is the best way to start.