Mighty Roar

(Savage Species, page 37, DnD 3.0)

[Monster]

You unsettle opponents with a dreadful roar as you attack.

Prerequisite

Animal or magical beast; Large size

Benefit

Once per day, you can use this feat as a standard action. Your mighty roar affects every opponent within 30 feet of you that can hear your roar and has a character level lower than yours. An affected opponent must make a successful Will save (DC 10 + 1/2 your Hit Dice + your Cha modifier) to negate the effect. Failure means that opponent becomes shaken for 1d6 rounds. A shaken creature takes a -2 morale penalty on attack rolls, checks, and saving throws.