Megafauna, Megatherium

As a standard action, the creature may perform an awesome blow combat maneuver. If the creature's maneuver succeeds against a corporeal opponent smaller than itself, its opponent takes damage (typically slam damage plus Strength bonus) and is knocked flying 10 feet in a direction of the attacking creature's choice and falls prone. The attacking creature can only push the opponent in a straight line, and the opponent can't move closer to the attacking creature than the square it started in. If an obstacle prevents the completion of the opponent's move, the opponent and the obstacle each take 1d6 points of damage, and the opponent is knocked prone in the space adjacent to the obstacle.

You do not provoke an attack of opportunity when performing a bull rush combat maneuver. In addition, you receive a +2 bonus on checks made to bull rush a foe. You also receive a +2 bonus to your Combat Maneuver Defense whenever an opponent tries to bull rush you.

You can choose to take a –1 penalty on all melee attack rolls and combat maneuver checks to gain a +2 bonus on all melee damage rolls. This bonus to damage is increased by half (+50%) if you are making an attack with a two-handed weapon, a one handed weapon using two hands, or a primary natural weapon that adds 1-1/2 times your Strength modifier on damage rolls. This bonus to damage is halved (–50%) if you are making an attack with an off-hand weapon or secondary natural weapon. When your base attack bonus reaches +4, and every 4 points thereafter, the penalty increases by –1 and the bonus to damage increases by +2. You must choose to use this feat before making an attack roll, and its effects last until your next turn. The bonus damage does not apply to touch attacks or effects that do not deal hit point damage.

You get a +3 bonus on all checks involving the chosen skill. If you have 10 or more ranks in that skill, this bonus increases to +6.