It counts as a simple melee weapon for you, and you add your Strength modifier to the attack and damage rolls when you attack with it, as normal.
Bite. Your mouth transforms into a boar tusks. It deals 1d8 piercing damage on a hit. Once on each of your turns when you damage a creature with this bite, you regain a number of hit points equal to your proficiency bonus, provided you have less than half your hit points when you hit.
Claws. Each of your hands transforms into a claw, which you can use as a weapon if it’s empty. It deals 1d6 slashing damage on a hit. Once on each of your turns when you attack with a claw using the Attack action, you can make one additional claw attack as part of the same action.
Tail. You grow a lashing, spiny tail, which deals 1d8 piercing damage on a hit and has the reach property. If a creature you can see within 10 feet of you hits you with an attack roll, you can use your reaction to swipe your tail and roll a d8, applying a bonus to your AC equal to the number rolled, potentially causing the attack to miss you
When you make your first attack on your turn, you can decide to attack recklessly. Doing so gives you advantage on melee weapon attack rolls using Strength during this turn, but attack rolls against you have advantage until your next turn.
You can rage 3 times per long rest.
While raging, you gain the following benefits if you aren't wearing heavy armor:
You have advantage on Strength checks and Strength saving throws.
When you make a melee weapon attack using Strength, you gain a +2 bonus to the damage roll.
You have resistance to bludgeoning, piercing, and slashing damage.
If you are able to cast spells, you can't cast them or concentrate on them while raging.
Rage ends early if you are knocked unconscious or if your turn ends and you haven't attacked a hostile creature since your last turn or taken damage since then. You can also end your rage on your turn as a bonus action.