Archgriffin

Flyby: The Archgriffin does not provoke opportunity attacks when it flies out of an opponents reach. 
Keen Sight: The Archgriffin has advantage on Wisdom (perception) checks made that rely on sight. 
Magic Attacks: All attacks made by the Archgriffin are considered magical.

Multiattack: The Archgriffin uses either it’s Poison Spray ability or its Stunning Shriek if either are available and makes four melee attacks: one with its beak, two with its clawed wings and one with its talons.

Beak: Melee Weapon Attack: +14 to hit, reach 10ft., one creature. Hit: 18 (2d10 + 7) piercing damage. 

Winged Claws: Melee Weapon Attack: +14 to hit, reach 10ft., one creature. Hit: 20 (2d12+7) slashing damage. 

Talons: Melee Weapon Attack: +14 to hit, reach 10ft., one creature. Hit: 20 (3d8+7) slashing damage, and the target is grappled (escaped DC 18). Until the grapple ends the target is restrained, and the Archgriffin can’t use its talons on another target. 

Acid Spray: (Recharge 5-6) Ranged Weapon Attack: range 30 ft cone, targets must make a DC 18 Dexterity saving this or suffer 40 (5d12+ 8) acid damage on a failed save or half as much on a successful one. 

Stunning Screech (Recharge 5-6) The ArchGriffin emits a powerful screech. Each creature within 20 feet of it that can hear it must make a DC 18 Constitution saving throw or be stunned until the end of the Archgriffin’s next turn. 

The Archgriffin can take 3 legendary actions per round. Only one legendary action option can be used  at a time and only at the end of another creature’s turn. The Archgriffin regains any legendary actions spent at the start of its next turn. 

Fly (Costs 1 Action). The Archgriffin moves up to its fly speed without provoking opportunity attacks. 

Frightening Presence (Costs 2 Actions). An aura of fear and despair surrounds the Archgriffin as it unfurls its feathery mane causing it to appear to be growing. Each creature within 30 feet of the Archgriffin that can see it must succeed on a DC 18 Wisdom saving throw or be frightened of the Archgriffin until the end of the Archgriffin’s next turn. If a creatures saving throw is successful, the creature is immune to the Archgriffin’s frightful presence for the next 24 hours. 

Savage (Costs 3 Actions). The Archgriffin makes a winged claw attack against each creature within 10 feet of it.