Defensive Needles

Your body is covered in sharp needles or spines which you can use to defend yourself. Each time you become Grabbed by a creature or an adjacent creature hits you with an unarmed attack, you twist and thrash your body around, dealing 2 piercing damage to that creature. This damage increases to 3 at 9th level, 4 at 13th level, and 5 at 17th level.