uncommon evocation monk shadow stance 

Cast [>] somatic

Duration until you leave the stance

You adopt the stance of clinging shadows. You can make shadow grasp Strikes. These deal 1d4 negative damage; are in the brawling group; and have the agile, grapple, reach, and unarmed traits.

While in clinging shadows stance, you gain a +2 circumstance bonus to Athletics checks to Grapple, and to the DC for creatures to Escape from you.

Advanced Player’s Guide, page 229.