PRPG->Feats-> Elephant Stomp - Enhancement

PFSRD

Elephant Stomp(Combat)

You deliver a crushing blow to downed enemies.

Prerequisite: Str 13, Power Attack, Improved Overrun, base attack bonus +1.

Benefit: When you overrun an opponent and your maneuver check exceeds your opponent’s CMD by 5 or more you can make one attack with an unarmed strike or a natural weapon against that opponent as a swift action.

When you overrun an opponent and your maneuver check exceeds your opponent's CMD by 5 or more, instead of moving through your opponent's space and knocking her prone, you may stop in the space directly in front of the opponent (or the nearest adjacent space) and make one attack with an unarmed strike or a natural weapon against that opponent as an immediate action.

Normal: When your overrun maneuver check exceeds your opponent’s CMD by 5 or more, you move through the target’s space and she is knocked prone.