BX Advanced Bestiary, Vol. 1

Volume 1 of the BX Advanced Bestiary takes the monster entries A-D from the OSE Basic book and expands them with options, added details, use for monster parts, additional monsters, and playable classes based upon the same theme. Each entry is illustrated.

It includes rules for monster and animal training, several new race-as-class options (advanced cave locust, changeling, cyclopskin, dragonborn, and genasi), as well tables showing the monsters organized by HD, terrain, and type.
Purchase of this book includes a free pdf, which can be downloaded from thirdkingdomgames.com by using the code found on the front page.