You latch on tight when larger creatures use their natural weapons on you.
Benefit: When a creature of a larger size category successfully hits you with a natural attack, you grab hold of the attacking appendage and latch on tight with a successful combat maneuver as an immediate action. While you are latched on you gain a +4 bonus to hit and damage rolls with shed light against this creature and lose your Dexterity, dodge, and shield bonuses to your armor class. You may also make attacks with only a single hand. The creature can dislodge you by performing a successful combat maneuver or Escape Artist check (DC equal to your CMD)