Burrowmaw

Shapechanger (Hybrid Form Only). The burrowmaw is permanently trapped as a fusion between a werewolf and a bulette. It cannot revert back to a humanoid form or animal form and is considered a monstrosity and a shapechanger.  

Pack Animal. When an ally is within 5 feet of an enemy, the burrowmaw has advantage on attack rolls against that enemy. 

Barbed Quills. When a creature starts its turn within 5 feet of the burrowmaw or hits it with a melee attack, the creature takes 4 (1d8) piercing damage. 

Regeneration. The burrowmaw regains 10 hit points at the start of each turn. If it takes fire damage or damage from a silvered weapon, this trait does not function until the end of its next turn. 

Ambush Predator. When the burrowmaw hits a creature that is surprised with a melee attack on the first round of combat, the target takes an additional 14 (4d6) slashing damage. 

Frenzied Surge (1/day). When the burrowmaw is reduced to half its hit point maximum (97 or below), it enters a frenzied state for 1 minute. In this state the burrowmaw gains the following traits:

• Movement speed is increased by 10 feet. 
• Makes an additional claw attack when taking the multiattack action. 
• Gains resistance to bludgeoning, piercing and slashing damage. 

Multiattack. The burrowmaw makes three attacks: one with its bite and two with its claws. 

Bite. Melee Weapon Attack: + 10 to hit, reach 10 ft., one target. Hit: 24 (4d8 + 6) piercing damage. If the target is a creature, it must succeed a DC 16 Constitution saving throw or be cursed with lycanthropy. 

Claw. Melee Weapon Attack: + 10 to hit, reach 10 ft., one target. Hit: 15 (2d8 + 6) slashing damage. 

Burrowing Lunge (Recharge 5-6). The burrowmaw dives into the ground and erupts at a point it can see within 30 feet. All creatures within 10 feet of the eruption must make a DC 16 Dexterity saving throw or take 22 (4d10) bludgeoning damage and be knocked prone. If the burrowmaw lands within 5 feet of a creature, it may make a bite attack against that creature as part of this action.

Tunnel Ambush. If the burrowmaw starts its turn while underground, it can use a bonus action to move up to its burrow speed and remain undetected unless a creature succeeds a DC 18 Wisdom (Perception) check. 

Quill Volley (Recharge 5-6). The burrowmaw launches a barrage of razor-edged quills in a 30-foot cone. All creatures in the cone must make a DC 16 Dexterity saving throw, taking 27 (6d8) piercing damage on a failed save, or half that much damage on a successful one.