From the introduction: "This is Warlock's Menagerie. It is a book designed to aid the referee of any fanasty role-playing game, especially the referee using the Warlock system or anything similar. This book assumes you have played, or are currently playing, some form of fantasy role-playing game, and are interested in refereeing such games, or are already doing so."

This is basically a reference supplement of monsters for the Dungeon Master.

Enlarged scans