• Fiend Folio
• 223 pages
• Wizards of the Coast
• MSRP: $29.95
• Nukeshop: Buy it from Amazon.com

The Fiend Folio is a legendary book in gaming circles. Released in 1981, the book was filled with all manner of monsters, created by authors in Great Britain and unleashed on unsuspecting 12-year-olds around the world. In addition to introducing a generation of American kids to oddities of British spelling (colour?) it also presented monsters that would go on to be staples of modern-day gaming.
These creations included the astral githyanki, the frog-like slaads and the implacable death knights, as well as other lesser creatures like iron cobras and hook horrors. It also introduced unicorn bunnies, flumps, lava children and an assortment of other creatures that were decidedly weird.
Twenty-odd years later, Wizards of the Coast has released a new Fiend Folio, one that evokes memories of horrific creatures from the earlier release, but which has a far tighter focus. This new focus is on extraplaner monstrosities, creatures that do not dwell on our earth, but instead inhabit terrible realities divorced from our own. These include the well known planes such as the demon-infested Abyss and the diabolic Nine Hells, as well as the less familiar (and more alien) Far Realm that exists beyond the boundaries of the multiverse. That said, there are also a fair number of creatures that dwell on the Prime Material Plane, though these can be just as bizarre as their otherworldly counterparts.
In addition to the monsters, the book includes two appendixes. The first presents three prestige classes for fiends: fiend of blasphemy, fiend of corruption, and fiend of possession. The second appendix covers an assortment of grafts and symbiots designed to grant special abilities and powers to monsters, including beholders, aboleths, and illithids.

Extraplaner Nastiness

As Dungeon Master, you can never have too many monsters, especially good monsters and the Fiend Folio offers plenty of these.
To start, the book offers lots of old favorites updaed to D&D 3.0, including the Yellow Musk Plant (and its spawn, the Yellow Musk Zombie), crypt things, iron cobras, and dark creepers. From what I saw, the conversions were true to the source material. The return of these monsters is great, and I plan to use a few in my game, but what really got me excited about this book are the new monsters.
The Kaorti, are wizards who once pierced the veil separating the multiverse from the Far Realm, traveled there and were transformed into alien monstrocities. They then traveled back to our reaility in order to close the breach they'd created in their earlier, human incarnation. They did so, but trapped themselves here in the process. Since our universe pains them physically, they barricade themselves inside fortress-like cysts. When they venture out, they do so in resin-encased armor, always looking for new victims to transform into more Kaorti. The monsters make for an excellent short story arc in any gaming group comfortable with extraplaner campaigning.
The Living Holocaust, a combination of air and fire elementals, provides a useful alternative to the standard fire elementals that veteran adventurers have grown accustomed to. The Quth-Maren is an undead monster consisting of exposed muscles stretched over a humanoid skeleton. It has caustic blood that burns any it touches, can control other undead, generates a fear effect, can regenerated, and can even spit its blood at enemies. It's an evil combination
Swarms -- a new monster type introduced in this book -- should provide a challenging new threat for characters used to fighting individual monsters, and who will now find themselves facing hundreds of tiny creatures forged together by a common will. Examples include abyssal ant swarms (which penetrate damage reduction with their acidic bites) and scarab beetle swarms (flesh-eating monsters undoubtedly inspired by The Mummy remake).
The Sporebat is a flying fungus that superficially resembles a flying bat, and which shoots a level-draining beam from its single orange eye. It's perfect for those nights when you're looking to introduce a little Lovecraftian horror into your game.
And the fiends? Well, there are plenty of them. The actual fiends -- like the scheming devils known as the Paeliryons, or the corpse-eating demons called maurezhi -- aren't particularly inspiring, but they're nice to have to round out the ranks of both the lawful and chaotic sides of the Blood War. What I liked better were the various constructs, like the hellfire and demonflesh golems, that while created by fiends, they don't fit into the standard cookie-cutter definitions of demons and devils, and thus can be useful as unexpected surprises for players.
The fiendish prestige classes are a great idea, particularly if you want to introduce a fiend into your campaign as something other just one-off boogymen. For example, the Fiend of Corruption prestige class provides a way of giving a fiend the extra abilities and skills it needs to be the perfect seducer of mortals. Give a fiend -- such as succubus -- a few levels of this prestige class and you've got an NPC capable of seducing all manner of mortals and giving the DM useful behind-the-scenes adversary for their players.
As far as the rules go, the Fiend Folio is something of an orphan. It was released a few months before D&D 3.5, and while some of its content foreshadows the upgraded edition, it's still very much a 3.0 book. For folks who've converted to 3.5, that's means that they'll have to convert all of the monsters to the new rules (particularly the bits about damage reduction). For those still playing 3.0 (like me), the book offers some of the niceties of 3.5 (like pre-calculated grapple attack values) without all the messiness of actually having to convert

Final Analysis

The Fiend Folio is excellent for campaigns that spend a fair amount of time plane-hopping, or for DMs who want to be able to spring something new and horrible on their players. What it's not good for though, is a traditional sword-and-sorcery campaign. Those most comfortable with dragons, orcs and goblins will find the creatures contained in this tome unsuitable.