Compared to other monster books I've read, this one is far from spectacular. It covers about 50 of the most generic and well known creatures, like dwarves, orcs, manticores, yetis, and zombies. I've baught it because the BESM 3rd Edition doesn't provide stats for any creatures, and because of the difference in Edition, you can't use the creatures right "out of the box". However, they make a good starting point for designing your own creatures and can be converrted quiete easily.
The main selling point is the small price. While I wouldn't pay any more for it, it is definately worth its monney.