Entity: Strong Oak

Source Impossible Lands pg. 36

Most ghorans have bodies of pliable vines and tough stems, but you're covered in sturdy, rough bark and your legs are stable as roots. You gain a +2 circumstance bonus on your Fortitude or Reflex DC against attempts to Grapple or Trip you. This bonus also applies to saving throws against effects that would grab you, restrain you, or knock you prone. You also gain a +2 circumstance bonus on Acrobatics checks to Balance.