Azdharchid (Quetzalcoatlus)

Dive Attack. If the quetzalcoatlus is flying and dives at least 30 feet toward a target and then hits with a bite attack, the attack deals an extra 10 (3d6) damage to the target.

Flyby. The quetzalcoatlus doesn’t provoke an opportunity attack when it flies out of an enemy’s reach.

Marathon Flight. The quetzalcoatlus can fly a maximum of 1000 miles/day on thermal updrafts at the expense of 1 point of exhaustion. The quetzalcoatlus must make a DC 10 Wisdom (Perception) ability check  every 250 miles flown to find new updrafts. On a failure, the quetzalcoatlus is forced to land and takes 1 point of exhaustion.

Bite. Melee Weapon Attack: +4 to hit, reach 10 ft., one creature. Hit: 12 (3d6 + 2) piercing damage. If the target is a Small or smaller creature, it must make a DC 12 strength saving throw or be swallowed. A swallowed creature is blinded and restrained, has total cover against attacks and other effects outside the quetzalcoatlus, and takes 5 (2d4) acid damage at the start of each of the quetzalcoatlus' turns.

The quetzalcoatlus' gullet can hold one creature at a time. If the quetzalcoatlus takes 20 damage or more on a single turn from a creature inside it, the quetzalcoatlus must succeed on a DC 20 Constitution saving throw at the end of that turn or regurgitate the creature, which falls prone in a space within 10 feet of the quetzalcoatlus. If the quetzalcoatlus dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 10 feet of movement, exiting prone.