pf2e.fyi
From Pathfinder Advanced Player's Guide, which isn't enabled.

Gorilla Stance

FEAT 1
Activity 1 action

You lower yourself to the ground and take an imposing, knuckle - walking stance.

While in this stance, the only Strikes you can make are gorilla slam unarmed attacks. These deal 1d8 bludgeoning damage; are in the brawling group; and have the backswing, forceful, grapple, nonlethal, and unarmed traits.

While you are in Gorilla Stance, you gain a +2 circumstance bonus to Athletics checks to Climb, and if you roll a success on an Athletics check to Climb, you get a critical success instead.

Pathfinder Advanced Player's GuideOGL