Arboren, Variant (5e Race Variant)
From D&D Wiki
This variant features new ability score increases and replaces Wooden Skin, Arboren Weapon Training, and Mask of the Wild.
Spiny Bark. Arboren have no need for sneaking, and attack head-on with their tough and spiny bark. You have advantage on checks against being grappled and deal piercing damage equal to your character level to any creature grappling you. For example: If you are level 20, you would deal 20 damage upon being grappled.