Alpha Dire Wyvern

Keen Sight. The wyvern has advantage on Wisdom (Perception) checks that rely on sight.

Flyby. The wyvern doesn't provoke opportunity attacks when it flies out of an enemy's reach.

Multiattack. The wyvern makes three attacks: two with its bite and one with its stinger. While flying, it can use its claws in place of one other attack.

Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one creature. Hit: 21 (4d6 + 7) piercing damage.

Claws. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 25 (4d8 + 7) slashing damage, and the target is grappled (escape DC 21). Until this grapple ends, the target is restrained, and the wyvern can't use its claws on another target.

Stinger. Melee Weapon Attack: +13 to hit, reach 15 ft., one creature. Hit: 21 (4d6 + 7) piercing damage. The target must make a DC 19 Constitution saving throw, taking 70 (20d6) poison damage on a failed save and becoming paralyzed until the end of their next turn. On a successful save the target takes half as much damage and is not paralyzed.

Roar (Recharge 5-6). The wyvern roars effecting each creature that can hear it within 80 feet of the wyvern. Each creature in that area must make a DC 19 Constitution saving throw or become stunned until the end of their next turn.

Wing Attack. When hit by a weapon attack the wyvern can beats its wings. Each creature within 15 feet of the wyvern must succeed on a DC 21 Dexterity saving throw or take 21 (4d6 + 7) bludgeoning damage and be knocked prone. The wyvern can then fly up to half its flying speed. If the triggering attack was a ranged weapon attack, the attack is deflected and deals no damage.