Air Form.

The mist hulk can enter another creature's space and stop there. It can move through a space as narrow as 1 inch without squeezing.

Death Burst.

When the mist hulk dies, it bursts in a wave of water. Each creature within 10 feet of it must make a DC 16 Dexterity saving throw. On a failed save, a creature takes 11 (2d10) bludgeoning damage and has the prone condition. On a successful save, a creature takes half as much damage only.

Actions

Multiattack.

The mist hulk makes two Slam attacks.

Slam.

Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 5) cold damage.

Hideous Wailing (Recharge 5–6).

The mist hulk releases a wail infused with magical anguish. Each creature within 30 feet of it must make a DC 14 Wisdom saving throw. A creature in the mist hulk's space has disadvantage on the saving throw. On a failed save, a creature takes 14 (4d6) psychic damage and has the incapacitated condition for 1 minute. The affected creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Mist Hulk