This pdf is 18 pages long, 1 page front cover, 1 page editorial, 1 page SRD, 1 page of advertisement, leaving 14 pages for the new monsters.

First of all, I do know that this book has been published in the very beginning of PFRPG and thus suffers from some problems of the first publications for any system. I picked this along the other books up at a fire-sale and thus didn't pay full price. The 3 fell beasts-files have since been lying around on my HD and I only recently unearthed them. So, how well has this book aged? Let's take a look at the critters:

This installment of the Fell Beasts series is somewhat different from its two predecessors - there is an underlying theme to some of the critters, namely a corrupt, unique and powerful evil elemental that can create undead via a relatively simple template (and unfortunately gets no artwork) and the Netherlord, a undead caster with both a potential weakness adventurers can exploit as well as some cool unique abilities I haven't seen before. Especially the latter is quite cool. Friends of anthropomorphic humanoids get a badger-like species including the necessary information for them to be used as (player) characters. There is also a steam-punkish construct, that while agile, didn't grip me. It's an ok critter, though. Fans of the pulp days of old get Man-apes (guess what they are) and a halfling-version of deep ones and hybrids inspired by H.P.Lovecraft's classic foes. The scorpion guard from Akkadian/Sumerian mythology also makes a comeback as a fey, though I'm not entirely sure I'd make the creature a fey myself. Unfortunately, they don't get an artwork. We also get fish with razor -like fins as both solitary creatures and as a swarm, but I prefer the version of the critter from Jon Brazer Enterprises Book of Beasts. Finally, the is a variant cyclops (whose artwork I don't like) and an undead animated set of armor that mentions "Animate Dead" in the rules-section, but lacks any elaboration on how it animates the dead.

Conclusion:
This installment of fell beasts suffers from none of the rather obvious formatting errors of the predecessors. Layout is ok, though the B/w-parchment look in the background is still not too printer-friendly. The b/w-artworks range in quality from ok to nice. However, in contrast to the first two books, not every creature gets its own artwork. While I didn't notice as many editing errors as in installment 1 and 2, they are still there. While they are not as grievous as to deter from the usage of the creatures, said undead set of armor does suffer from exactly that. That being said, the netherlords are creatures that just ROCK and that I will actually use, which is more than can be said about the other creatures from the predecessors. While overall quality has improved, for the price and with regards to what you can get elsewhere, I'll rate this book 2.5 stars, rounded down to 2.

Much like the first two volumes, there are some solid, "your PCs haven't seen this before" monsters in here, and its not too bad for the price of the book.

Still, taken as a whole, you should probably read through the volumes of this series and pick and choose the ones that feel the most compelling. Without any "must haves," you may not want to spend too much on utility or novelty monsters to throw into the campaign.