From publisher blurb:
Unnatural Creatures of Unspeakable Evil
Trembling hands have recorded horrifying stories of encounters with aboleths, beholders, mind flayers, and other aberrations. The victims of these alien creatures are quickly overwhelmed by mind-numbing terror - their only comfort is the hope for a quick death.
This supplement for the D&D game presents a comprehensive look at some of the most bizarre creatures ever to invade the world of fantasy roleplaying. Along with information about the physiology, psychology, society, and schemes of these strange beings, you’ll find spells, feats, tactics, and tools commonly employed by those who hunt them.
Lords of Madness: The Book of Aberrations also provides new rules, prestige classes, monsters, sample encounters, and fully developed NPCs ready to instill fear in any hero.