Multiattack. The wyvern makes two attacks: one with its bite and one with its stinger. While flying, it can makes three attacks: two with its claws and one with its stinger.

Bite. Melee Weapon Attack: +9 to hit, reach 10 ft., one creature. Hit: 20 (4d6 + 6) piercing damage.

Claws. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 24 (4d8 + 6) slashing damage.

Stinger. Melee Weapon Attack: +9 to hit, reach 10 ft., one creature. Hit: 20 (4d6 + 6) piercing damage. The target must make a DC 19 Constitution saving throw, taking 35 (10d6) poison damage on a failed save, or half as much damage on a successful one.

Tail. Melee Weapon Attack: +9 to hit, reach 15 ft., one target. Hit: 20 (3d8 + 6) bludgeoning damage.

Wyvern Roar (Recharge 5–6). The Wyvern releases a powerfull roar, Each creature within 15-­feet of the Wyvern must make a DC 19 Constitution saving throw, taking 42 (12d6) thunder damage on a failed save and be pushed 10 feet, or half as much damage on a successful one.

The Wyvern can take 3 legendary actions. Only one legendary action option can be used at the end of another creature's turn. The Wyvern regains spent legendary actions at the start of its turn.

Tail Attack. The Wyvern makes a tail attack.

Wing Attack (Costs 2 Actions). The wyvern beats its wings. Each creature within 10 feet of the wyvern must succeed on a DC 18 Dexterity saving throw or take 13 (2d8 + 4) bludgeoning damage and be knocked prone. The Wyvern can then fly up to half its flying speed.