From the back of the book:
Inside the Battlezoo Bestiary, discover a treasure trove of over 100 brand-new monsters and villains for your players to confront and overcome at your next game! The creatures in this epic tome represent the best and beastliest submissions from the 2020 RPG Superstar contest, including monstrosities like the sailor-snatching muted delver, the spore-sowing fungal raptor, and the mind-melting orb of insanity.
The Battlezoo Bestiary also includes the new Monster Parts system—perfect for monster slayers who want to turn all those freshly collected ardeodaemon horns and parrotbear feathers into custom items and equipment. Completely compatible with Pathfinder Second Edition and full of rich inspiration for any fantasy game system, this book is a one-of-a-kind compendium useful for Game Masters and players alike.