As two actions, you transform your body into living oak. Until the spell ends, you have resistance to bludgeoning, piercing, and slashing damage from attacks. You have vulnerability to fire damage, but you are immune to the blinded, deafened, disease, and poisoned conditions. You cannot drown as you have no physiology or respiration while this spell is in effect. You cannot drink (and thus can’t use potions) or play wind instruments.
You have advantage on Strength checks. Additionally, your unarmed attacks deal 1d8 bludgeoning damage and are considered magical.