Terrifying Strike

(Drow of the Underdark, page 54, DnD 3.5)

[Ambush]

Your sneak attacks inspire fear.

Prerequisite

Intimidate 4 ranks, Sneak attack +2d6

Benefit

The target of your sneak attack is shaken for 1 round. This effect doesn't stack with any other fear effects, including itself. This is a mind-affecting fear effect. Using this feat reduces your sneak attack damage by 1d6.