Silver Age Sentinels: From the Files of Matthews Gentech

Imagine a research company capable of manipulating and combining the genetic structure of any animal. Now imagine that it's under the control of a maniacal genius who hates all super-heroes and desires to wipe them from the face of the Earth. Welcome to the Matthews GenTech files: a collection of custom-made creatures (complete with both Tri-Stat and d20 System game statistics) designed to take down Empire City's beloved super-heroes.