Fantasy AGE and Green Ronin's Adventure Game Engine as a whole, has been one of my favorites since it launched with Dragon Age.
The Fantasy AGE Bestiary is a welcome edition to the line. It's beautifully illustrated and very appealing to the eye.
Full disclosure I was given a PDF for review purposes.
Section 1 discusses the book and it's contents and gives guidelines for upgrading an adversary to Elite, Heroic, or Epic in strength. The upgrade guidelines are each about a paragraph and straightforward to enact.
Section 2 covers 67 antagonists and their variants. Each creature is given an illustraion and a minimum of two pages, which covers their folklore, they type of antagonist they are, several adventure hooks, their stat blocks and what level of Threat they are. The folklore draws from cultures all over the world and I truly appreciate that. And the adventure hooks could easily provide for a night's adventure.
I want to reiterate that the art for each creature and the layout are top-notch.
Creatures range from chimera, formoiri, morlocks, mothmen, shadow people, thin men, trolls, and weresaurs (werevelociraptors).
Section 3 covers more mundane beasts of all kinds, 18 in all. This where you find swarms of bats, dogs, and giant squid. No illustrations are presented, and I didn't find them necessary.
Section 4 opens with an in-depth examination of modifying monsters and presents 35 special qualities that can be applied to any antagonist. These things like Berserker, Blending, Eldritch, Magic Resistance, Pack Advantage, Shifting, Sunblighted, and Winged.
Next up are guidelines for combining special qualities to form specific templates to apply to antagonists and an example, the "mad machine" template is provided.
After this is a discussion of borrowing other creature's special abilities as qualities for other antagonists.
It follows with a discussion on using Talents and Focuses for further customization.
A side-bar on the collateral damage from large, powerful menaces presented within the Bestiary.
A brief discussion on having antagonists use magic items for the player's to find as loot as a common trope of the genre. It does discuss how, if possible, the antagonist could easily wield the item against the players.
Next is a discussion in simply reskinning monsters for your needs and with all the tools presented in this section, when combined with the rest of the book, have easy and useful tools to create numerous enemies with a minimum of time.
Pros Green Ronin makes great books and if your a fan of the AGE system, the book is indispensable. The presentation and tone of the Bestiary reminds of a worth successor to the Old World Bestiary, that members of the company designed for Warhammer Fantasy 2nd Edition for Black Industries. Which, for me, is high praise.
Cons if you don't play the AGE system, it's got some great inspiration but would require some work.
My Advice buy this book if you enjoy the Adventure Game Engine.