Horde Book 1: A Swarm of Stirges

From Gamegrene.com - For The Gamer Who's Sick Of The Typical:

This book is the first in the innovative Masters and Minions series from Behemoth3. The series takes a second, closer look at monsters from the early days of D&D, and provides GMs with something much, much more than just a goofy looking critter to suck hit points from the PCs before they meet the villain. A Swarm of Stirges gives the stirge some things it has always lacked: a complete life-cycle, a place in the ecosystem, a raison d'etre. Unfortunately, Stirges is a collection of many incredibly cool ideas and one monumentally bad one. Read more from this post.