From Kickstarter campaign:
An all-new, full-color, 128-page hardcover book of creatures is here to help any Game Master put her players to the test.
GMs and players are always hungry for fresh challenges in the amazing world of Golarion. The Bestiary 2 gives you dozens of new enemies to encounter, from a wide range of outsiders, such as aeons and daemons to creatures native to the material plane, such as sphinxes and dinosaurs.
The new creatures in this book will test adventuring parties of every Rank. From the lowly basidrond that causes hallucinations to the legendary Jabberwock, Game Masters can craft a wide range of encounters for their heroes to overcome. What's more, using the Improved Familiar Edge (included in the Advanced Player's Guide 2) players can tame some of these creatures to become familiars.