Under Roc

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

Darkvision. The under roc can see in darkness up to 120 ft.

Reflective Scales. The under roc has advantage on Dexterity (Stealth) checks.

Multiattack. The roc makes two attacks: one with its beak and one with its tail slap.

Beak. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 17 (2d8 + 8) piercing damage and the target must make a DC 15 Constitution saving throw. On a failure, the target takes an additional 20 (3d8 + 5) poison damage and becomes poisoned for 1 minute. The target may repeat this saving throw at the end of each of its turns

Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 23 (4d6 + 8) slashing damage, and the target is grappled (escape DC 18). Until this grapple ends, the target is restrained, and the under roc can't use its bite on another target.

Tail Slap. Melee Weapon Attack: +10 to hit, reach 10ft., one target.  Hit: 25 (4d8 +8) bludgeoning damage and must make a DC 18 Strength saving throw or be pushed 20ft away. 

Launch. Radius Effect: Any creature within 15 ft of the under roc must make a DC 18 Strength throw. Any creature that fails takes 16 (2d6 + 8) bludgeoning damage, is pushed 15 ft away. Creatures that succeed take half damage and are not pushed. The under roc then flies 60 ft up in the air and must take the Crash action on the next round.

Crash. Radius Effect: The under roc chooses a point within 120 ft of where it used the Launch action and crashes into the ground. Creatures within 15 ft of the under roc's landing must make a DC 18 Dexterity saving throw. Creatures that fail take (4d12 + 9) bludgeoning damage and are knocked prone. On a success, creatures take half damage and are not knocked prone.

  The under roc also takes appropriate falling damage from using its Crash attack.