Ashen Fliers. The dragon can breathe in any area that has an amount of air or smoke, regardless of how thin. It can hold its breath for up to an hour at a time.

Claret Scales. The dragon's flight speed is doubled while in smoke. In smoke, if the dragon moves at least 60 feet in a straight line before attacking, the attack deals an additional 21 (6d6) damage. The dragon cannot swim.

Fade Into Fog. The dragon can use its action to shapechange into a mass of semisolid smoke (or back to its dragon form). While in this form, the dragon makes stealth checks at advantage and loses its walking and climbing speeds, but gains the hover property.

Spellcasting. The dragon is an innate spellcaster. Its spellcasting ability is Charisma (spell save DC 19, +11 to hit with spell attacks). The dragon knows the following spells and can cast them at their lowest levels without material or somatic components:
Cantrips (at will): Fire Bolt, Produce Flame, Mage Hand, Druidcraft

5x/day: Burning Hands, Chromatic Orb (always chooses fire damage)

3x/day: Fireball

1x/day: Wall of Fire, Immolation

Multiattack. The dragon makes three attacks: one with its bite and two with its tail.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 17 (2d10+6) piercing damage plus 14 (3d8) fire damage.

Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit. 19 (2d12+6) bludgeoning damage.

Smoke Breath (Recharge 5-6). The dragon exhales a suffocating wall of burning smoke in a 40­-foot cone. Each creature in that area must make a DC 19 Constitution saving throw, taking 70 (14d8) fire damage on a failed save, or half as much damage on a successful one. The area of the cone is lightly obscured to all creatures but the dragon for the next round, and the dragon has half cover.

Dodge 3x/day. The dragon takes the dodge action as a bonus action. Once the dragon is hit with an attack, the dodge ends.

Burst. The dragon may use its reaction to burst in a cloud of smoke when a creature enters its reach. When the dragon uses its reaction in this way, it has three-quarters cover for the duration of the triggering creature's turn.