From publisher blurb:
Aquilae: Bestiary of the Realm is the largest, most comprehensive, most flexible, and most ambitious fantasy roleplaying bestiary ever conceived. 6,400 complete statblocks, comprising 1,600 monsters, each given the Quadded Statblock treatment, enabling them to be used in any campaign setting, with PCs of any level.
Add to this a thoroughly innovative and massively expandable AI system to guide monster behavior, and you have what just might be the most impressive and valuable creature resource ever to hit Pathfinder Second Edition.
(Please note that Aquilae: Bestiary of the Realm in its entirety is a six-volume set. This publication is the first of those six volumes, and contains 1,064 statblocks comprising 266 monsters.)