
Beyond those three major races, we found a couple of others that shared some similar characteristics but were not as iconic to the game - the neogi and the grell. They're highly intelligent, they enslave other monsters, and they're particularly inimical to human life and society. Rich Baker explains how the book's designers chose the creatures with which they worked: "The best master aberrations we identified were the aboleths, beholders, and mind flayers. This book is part of a series of books regarding specific monster types, which includes the Draconomicon and Libris Mortis. Wayne England and Ed Cox drew the cover art, and the interior art was by Steve Belledin, Mitch Cotie, Ed Cox, Dennis Crabapple McClain, Steve Ellis, Wayne England, Colin Fix, Dana Knutson, Doug Kovacs, Chuck Lukacs, Jim Nelson, Michael Phillippi, Wayne Reynolds, Richard Sardinha, Dan Scott, and Ron Spencer. Lords of Madness was written by Rich Baker, James Jacobs, and Steve Winter, and was published in May 2005.


"The Eaters": Provides information on the grell, including their anatomy, society, and magic."The Slave Takers": Provides information on the neogi, including different types of neogi, their anatomy, and magic."The Mind Flayers": Provides information on the illithid, including their anatomy, variant creatures, and magic."The Eye Tyrants": Provides information on the beholder, including their anatomy, variant creatures, a prestige class called the Beholder Mage, feats, and magic."The Deep Masters": Provides information on the aboleth, including their anatomy, variant creatures, a prestige class called the Savant, feats, and magic.Also provides details on how to run a campaign based on aberrations. "What Is an Aberration?": Defines what characteristics make a creature an aberration, and how these creatures originated.

The book includes new content for aberrations including new aberration monsters and monsters related to them, and information on how to hunt aberrations.
