Andreas Walters has put together a fantastic book that is part monster manual, part field guide, part ecology book and a huge part art book.
The book is a densely packed 81 full-color pages. Easily one of the best-looking books to be nominated for an ENnie. Each monster description comes with details on what the young of each monster is called (a baby Hippocampus is known as a "fry" for example), how hard it is to train the young and other vital facts such as danger and intelligence levels.
The book would make for a great coffee table book really and I hope there is a nice leatherbound option in the future collecting both volumes.
Of course, the obvious choice here is the older gamer that has kids that LOVE monster books.
I have forgotten how many times I have had to go on rescue missions to my kids rooms to find my D&D books. I still have a Pathfinder book that I can't account for in fact! For younger kids a "baby monster" game, ala Pokemon, gotta catch them all, would be fantastic.
Since there is little to no "crunch" in this book it is compatible with a wide variety of games. Play your favorite game, use this book as your guide and go monster hunting with your kids.
In any case, this is a really fun book and I am really looking forward to Volume 2.