Your charge sends foes reeling away, knocking them to the ground.
Benefit: When you hit an opponent with a charge attack, you might also initiate a bull rush as a free action. This does not require you to move into your opponent’s square and does not provoke an attack of opportunity. If you successfully push your opponent 15 feet or more, he is also knocked prone.
Section 15: Copyright Notice – Classic Monsters Revisited
Classic Monsters Revisited. Copyright 2008, Paizo Publishing, LLC; Authors: Wolfgang Baur, Jason Bulmahn, Joshua J. Frost, James Jacobs, Nicolas Logue, Mike McArtor, James L. Sutter, Greg A. Vaughan, Jeremy Walker.