Death Master

(Libris Mortis: The Book of the Dead, page 26, DnD 3.5)

[Monster]

Foes are especially afraid of your critical hits.

Prerequisite

Daunting Presence, CHA 13, undead type, base attack bonus +1

Benefit

Whenever you score a critical hit with a melee attack against a living foe, the foe is also shaken for 1 minute. This is a mind-affecting, fear effect.