User will have fangs.

Pros:
-user can bite through anything
-user will have a strong jaw
-user will have indestructible teeth

Cons:
-teeth are painful to grow
-user can't digest inedible food
-user will snore, loudly
-no other physical advantages

Weakness: poison
User will does quickly are their teeth will absorb some and weaken the skeleton, digestion of next.