Anzu

Augmented critical. When the anzu scores a critical hit it deals triple the normal damage. 

See invisibility. The anzu can see any creature that is invisible that is within 60ft of them.  

Slick. The anzu is constantly under the effect of the freedom of movement spell but can have this ability nullified for 1d6 hours if they take fire damage. 

Telekinesis mastery. When ever the anzu uses its telekinesis from its innate spellcasting has a few changes including the following: It can move up to 2 objects or creatures at a time, doesn't require concentration and the duration is permanent until the anzu dispels the effect. 

Magic Resistance. The anzu has advantage on saving throws against spells and other magical effects.

Magic Weapon. The anzu's weapon attacks are magical.

Innate Spellcasting. The anzu’s innate spellcasting ability is Charisma (Dc 18, +10). It can innately cast the following spells, requiring no material components:

At will: banishment, blight, greater invisibility, telekinesis, teleport

1/day each: magic weapon, project image, true seeing

Multi attack. The anzu makes one bite attack, four wing attacks and a talon attack.

Bite. Melee Weapon Attack: +13 to hit, reach 15 ft., 1 target. Hit: 18 (3d6 + 9) piercing damage and the target must make a dc 19 Constitution saving throw or be poisoned for 1d4 rounds and if the attack misses each creature within 5ft of the anzu must make a dc 19 Constitution save or take 12 (6d4) poison damage. 

Wing. Melee Weapon Attack: +13 to hit, reach 15 ft., 1 target. Hit: 13 (1d8 + 9) bludgeoning damage. 

Talon. Melee Weapon Attack: +13 to hit, reach 15 ft., 1 target. Hit: 12 (1d6 + 9) slashing damage. 

Variant: Summon Demon (1/Day). The demon chooses what to summon and attempts a magical summoning.

An Anzu has a 30 percent chance of summoning 1d6 vrocks or another anzu.

A summoned demon appears in an unoccupied space within 60 feet of its summoner, acts as an ally of its summoner, and can’t summon other demons. It remains for 1 minute, until it or its summoner dies, or until its summoner dismisses it as an action.