From back cover:
Xenoforms. For years we've asked the question: Are we alone? But what if we don't like the answer?
Xenoforms: Aliens, Demons, and Aberrations is a compendium of creatures for the DARK-MATTER(TM) campaign setting. These previously uncataloged beings come from the farthest reaches of space and the depths of our oceans, from the deepest jungles and worlds outside our universe. They live among us, unseen except by thos brave enough to seek them out.
In this 96-page book you'll find nearly fifty detailed descriptions and illustrations of the aliens that visit our world, the creatures that evolved alongside us, and the strange variations we have made of our own species. Also included are adventure suggestions designed to bring characters and creatures together--whether the heroes are ready to face them or not.