Medieval Bestiary: Revised Edition is an excellent book. It is a revision of an earlier work, but done so well that it stands better on its own. It might be called, essentially, a "Monster Manual," but it is so much richer and detailed than that, containing varied and inspiring examples of historical myth and legend. It details the many, many beasts of medieval Europe, and intelligent rules for designing your own. Furthermore, it neatly solves the difficult question presented by the earlier work, "Are all creatures of medieval Europe magical?" No, says Kasab's Medieval Bestiary, just some of them (Beasts of Virtue), and they tend to be special. And beyond the well-written content, the presentation and layout are well done; it is simple to comprehend and easy to read, and the index is useful and accurate. I cannot imagine playing an Ars Magica saga without this book.