Note that this isn't a review. I edited this book in return for a free copy and some other goodies so there's no way I could be called objective about it.
What is the Teratic Tome? It's a monster manual chock full of horrors. And I do mean horrors; the monsters in this book tend to express aspects of body horror, religious-based terrors, and sexual anxieties. Whereas TSR's Monster Manuals tended to re-purpose monsters from folklore, myths, and legends, the Teratic Tome mines the same spot in the collective unconscious that Clive Barker, David Cronenberg, and Thomas Ligotti have been working in throughout their careers. Many of the monsters therein are culled from Raphael Chandler's Dread and Spite.
What is great about the Teratic Tome? Generally monster books present you with a creature's stats and general habits; this one gives you both motivations for the monster's behavior and its modus operandi. These bits are filthy with plot hooks--you will read each entry and immediately want to put that monster into your game. The Teratic Tome also does a great job "filling in" mid- and high-level niches in D&D games.
I also like a great deal of the art. I even like the cover style of the book, somewhat despite myself. I don't usually like modern products that ape the style of TSR's "classic days," but instead of being a copycat product the Teratic Tome looks like it fell through a wormhole into our world from one that was playing a very different version of D&D in the 1970s.
Who isn't likely to want this book: people who are bothered by grotesque sexualized art, people who are bothered by grotesque sexualized monsters in general, people who demand a pure Tolkien or high fantasy feel from their gaming products.
The Teratic Tome can be had here.