Pack Tactics. The Wyvern Brute has advantage on an attack roll against a creature if at least one of the Wyvern Brute's allies is within 5 feet of the creature and the ally doesn’t have the Incapacitated condition.

Multiattack. The Wyvern Brute makes two Rend attacks, one Bite attack and one Sting attack. The Wyvern Brute can replace the Sting attack with a Tail attack.

Bite. Melee Attack Roll: +9, reach 5 ft. Hit: 13 (2d8 + 4) Piercing damage plus 7 (2d6) Poison damage.

Rend. Melee Attack Roll: +9, reach 10ft. Hit: 13 (2d8+4) Slashing damage.

Sting. Melee Attack Roll: +9, reach 10 ft. Hit: 13 (2d8 + 4) Piercing damage plus 31 (7d8) Poison damage, and the target has the Poisoned condition until the start of the Wyvern Brute’s next turn.

Tail. Strength Saving Throw: DC 16, One creature of size Large or Smaller, the Wyvern Brute can see within 15 feet. Failure: 14 (2d12+4) Bludgeoning damage, and the target has the Grappled Condition (Escape DC 16). While grappled, the target has the Restrained condition and the Wyvern Brute cannot target a creature other than the grappled creature with the Sting attack.

Nimble Escape. The Wyvern Brute takes the Disengage or Hide Action.

Parry. Trigger: The Wyvern Brute is hit by a melee attack roll while not grappling a creature with its tail. Response: The Wyvern Brute adds 3 to its AC against that attack, possibly causing it to miss.