Jawbone Shield

Armor (shield), very rare (requires attunement)

This +1 shield is comprised of a massive plate of dinosaur bone with jagged, tooth-like ridges ringing its edge.

As a bonus action, you can make an attack roll with it, as if it were a +1 weapon that deals 1d4 slashing damage. You have advantage on any rolls made to prevent the shield from being disarmed due to the sharp edges. When a creature larger than you attempts to grapple you, it provokes an opportunity attack from you; this attack must be made using the jawbone shield. When you are attacked by a creature using a Bite as their attack you can make an opportunity attack against them, and in addition to dealing damage, you damage the biting creature’s jaws unless it succeeds on a Constitution saving throw with a DC of 8 + your Strength modifier + your proficiency bonus, causing it to take disadvantage on attack rolls with its Bite attack for 1d4 days. Once you use this ability, you cannot use it again until you complete a short or long rest.

Epic Attunement. You can use the ability to damage a creature’s jaws an unlimited amount of times per day. If a creature with damaged jaws fails another saving throw against this ability, they lose the ability to make bite attacks for 1d4 days. In addition, when attacking with the jawbone shield, you can change the damage dealt to 1d8 slashing damage. You can use this ability a number of times equal to your Strength modifier, after which you cannot use it again until you complete a long rest.