Even creatures much bigger than you can lose their balance when you apply the appropriate leverage.
Benefit(s): Choose one weapon with the reach special quality. When you attempt a trip combat maneuver check with the chosen weapon, you can try to trip creatures that are up to two size categories larger than you. If you have the Greater Weapon Focus feat with the chosen weapon, you can attempt to trip creatures up to three size categories larger than you are.
Normal: You can trip only an opponent who is no more than one size category larger than you.
Special: In addition to the chosen weapon, a character with the weapon training class feature can use Titan’s Tangle with any melee weapon from any fighter weapon group that he has selected with weapon training and that has the reach special quality.
Pathfinder Player Companion: Martial Arts Handbook © 2018, Paizo Inc.; Authors: Thurston Hillman, Mikko Kallio, Jacob W. Michaels, Matt Morris, Daniel Reed, Mikhail Rekun, Mark Seifter, and Jeffrey Swank.