Ghast

Stench. A creature that starts its turn within 5 feet of the ghast makes a DC 10 Constitution saving throw. On a failure, it is poisoned until the start of its next turn. On a success, it is immune to any ghasts Stench for 24 hours.

Turning Defiance. The ghast and any ghouls within 30 feet make saving throws against being turned with advantage.

Undead Nature. Ghouls and ghasts dont require air, sustenance, or sleep.

Paralyzing Claw. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage. If the target is a living creature it makes a DC 10 Constitution saving throw. On a failure the target is paralyzed for 1 minute. The target repeats the saving throw at the end of its turns ending the effect on itself on a success. If the targets saving throw is successful or the effect ends for it it is immune to any Paralyzing Claw for 24 hours.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one incapacitated creature. Hit: 8 (1d10 + 3) piercing damage.