Aerodactyl

Reckless. At the start of its turn, Aerodactyl can gain advantage on all melee weapon attack rolls it makes during that turn, but attack rolls against it have advantage until the start of its next turn.

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

Multiattack. Aerodactyl 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: +7 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4)Piercing damage. If the target is Medium or smaller, it is considered grappled (escape DC 16) and the Aerodactyl cannot make another bite attack while it has a target grappled in this manner.

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 13 (2d8 + 4) Slashing damage. 

Stinger. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4) Piercing damage. The target must make a DC 18 Constitution saving throw, taking 24 (7d6) Poison damage on a failed save and half as much damage on a successful one.

Screech. The Aerodactyl lets out a loud, piercing screech. Each creature within 30 feet of it that can hear the screech must make a DC 15 Constitution saving throw, taking # (#d#) Thunder Damage and become deafened on a failed save and half as much damage on a successful one.

Agility. When Aerodactyl moves its full movement speed in a straight line; it can also dash as a bonus action.