Ash wraiths are the undead, burnt remains of corpses. They take the form of a swirling cloud of gray-black ash, usually vaguely humanoid in shape. Although they cannot properly be said to have corporeal bodies, their touch retains the passionate heat of their deaths and is scalding to mortal flesh.
Hauntings. Ash wraiths are most often found haunting ruined crematoriums or lingering near the horrors of execution pyres, but there are also tales of woods being haunted by ash wraith animals for years or even decades after the devastation of forest fires.
From One, Many. Ash wraiths can be created using the animate dead spell, although it requires special knowledge to do so.
Necromancers who perfect the rare art of creating ash wraiths are often able to claim two undead servants from a single corpse. Although the rites which create a skeleton usually consume the flesh of the corpse (if it has not already rotted away), a necromancer can first flense the corpse. The flesh and fat is then burned, providing the ashes for the wraith, while the skeleton is animated separately.
Undead Nature. An ash wraith doesn’t require air, food, drink, or sleep.
ASH WRAITH
Medium undead, neutral evil
Armor Class 12
Hit Points 18 (4d8)
Speed 0 ft., fly 30 ft. (hover)
STR 7 (-2), DEX 14 (+2), CON 11 (+0), INT 6 (-2), WIS 8 (-1), CHA 5 (-3)
Damage Resistances acid, cold, fire, lightning, thunder; bludgeoning, piercing, and slashing from nonmagical weapons
Damage Immunities necrotic, poison
Condition Immunities exhaustion, grappled, poisoned, prone, restrained
Senses darkvision 60 ft., passive Perception 9
Languages understands all languages it knew in life, but can’t speak
Challenge ¼ (50 XP)
Proficiency Bonus +2
Ashen Movement. The ash wraith can move through other creatures’ spaces as if they were difficult terrain.
Undead Embers. If damage reduces the ash wraith to 0 hit points, it must make a Constitution saving throw of DC 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the ash wraith will reform in 1d4 hours.
ACTIONS
Fiery Touch. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 5 (1d6+2) fire damage.
Design Note: Ash wraiths are designed to provide an incorporeal form of undead that can be used in a fashion similar to skeletons and zombies. (In other words, minor undead that aren’t mind-searingly terrifying.) They were originally created for the original 1974 edition of D&D, and that stat block can be found here.
These would make a great replacement for the ash zombies encountered in Lost Mine of Phandelver. Though they’re the same CR, ash wraiths are far more interesting, and make a lot more sense in the remains of a village consumed by burning volcanic ash.