There are over 100 template. Any template that was used and updated by Paizo for their Bestiary were removed and new ones were slotted in. So if you enjoy tinkering with your run of the mill monsters this book is for you. You can create 100 plus different variants of a goblins. Can't wait to read through this book. Check out some of the pictures.
You can get the book at
Advanced Bestiary on Paizo
Advanced Bestiary on Green Ronin