From the Back of the Book:
Imagine a race of lycanthropes so devious, so cunning, and so insidious that they conquer entire kingdoms without ever being seen. These are the wererats. Their secretive broods infiltrate key posts in the government, military, and guilds, ensuring political protection from their enemies. When fighting can't be avoided, the mystic Council of the Flesh unleashes its horrific cross-bred monsters, which never give a hint as to their wererat origins. When nothing else works, the hard-hearted Weavers spread filth and disease, eliminating entire cities with a single contaminated breath. Kingdoms fall, power changes hands, and the enemies of the wererats are exterminated, without a single outsider ever knowing how.
The Complete Guide to Wererats is a stand-alone, world-neutral sourcebook covering everything you ever wanted to know about wererats. It includes:
Detailed background material on wererat broods and their insidious plans, including social structure, cultural habits, and combat tactics.
Details on the secretive Council of the Flesh and their lycanthropic madness, including stats for the horrible creatures they have created.
New feats, classes, and skills for wererats and other shapechangers.