Pathfinder RPG 2nd Ed: Bestiary Hardcover - Rules of Play says:

More than 400 of fantasys fiercest foes burst from the pages of this enormous 360-page compendium of the most popular and commonly encountered creatures in the world of Pathfinder! From familiar enemies like orcs, dragons, and vampires to new horrorslike the living-nightmare nilith and the three-headed mutoli, to suitable servants for summoners of every alignment, this must-have companion to the Pathfinder Core Rulebookis crawling with creatures perfect for your Pathfinder adventures!