From the back cover:
"All Things Vile and Murderous ..."
"Some creatures are tragically misunderstood – fearsome in appearance, but basically harmless, or even good.
"But the ones in this book are just plain rotten.
"GURPS Monsters contains 48 of the meanest, vilest people, animals, and things to infest this (or any other) universe."
Includes monsters from classical and modern myth as well as wholly new foes. Has a chapter on playing monsters and the people who hunt them.