Shatter Resolve (4e Feat)
From D&D Wiki
"Flee for what little your life is worth while you can still writhe." Your Intimidate skill is increased by +2, and critical Intimidate rolls now terrify the victim into a state of cowering panic.
Benefit: Your snarled voice backs its words with bestial wrath, and shatters even the greatest of resolves, breaking their will and forcing them into a state of cowering panic when you level your ire against them, increasing your Intimidate skill by +2. Successful Intimidate rolls that are critical (natural 20) instantly cause the target to panic, making it flee by the fastest means it can; while panicked it can take no actions, and suffers a –2 penalty on all saving throws, skill checks, ability checks, and AC. It must succeed in saving throw to end the panicked effect. This state of panic lasts until the end of the Encounter or until the creature succeeds in its saving throw.
Special: Outside of combat you may instead choose to immobilize the target, paralyzing it with fear, which allows it to still speak, but prevents it from taking any action or movement and reduces its AC by -2. It must succeed a saving throw to end the cowering effect. Creatures paralyzed with fear or terrified to the point of fleeing will break their state of panic should you leave them alone for an extended period of time.