It contains biographies and gaming statistics for forty-eight monsters for various campaign settings.

Johnson served for five years as the first coordinator of GURPS errata for Steve Jackson Games.

[1] He has also designed a few computer games, including gToons for Cartoon Network.

[3] GURPS Monsters won a rating of A in a review published in Games Unplugged.

[4] John G. Snyder of gamingreport.com rated the book at 4 1/2 stars, saying, "You will be pleasantly surprised and not a little disturbed.