The fourth in the series of Monstrous Menaces maintains the quality of the previous three offerings. The author, James Mishler, provides interesting and unique characteristics for each monster that translates directly into actual game play. You get plenty of ecological information and tactical details that all add richness to the game without overworking the harried GM/DM/CK/Ref.
The hribixul is a great wilderness monster that will be a challenge for any party of adventurers. The memnech is less likely to be used as a random creature, but gives the GM/DM/CK/Ref a nice creature to when a campaign needs direct interaction by otherwise distant and removed deities. The quasi-dragon is similar to the pseudo-dragon in name only--the quasi-dragon being a large, primitive dragon-like creature (maybe the missing link between large reptiles and the dragon?).
The monsters are setting neutral--despite the detail provided, the GM/DM/CK/Ref will have a set of monsters that are usable in almost an campaign setting. And, despite the Castles & Crusades template, can fit right into any traditional fantasy role playing game with minimal work.