Dragon, Dust (Ancient)

Gargantuan dragon, neutral evil

Armor Class 22 (natural armor)
Hit Points 487 (25d20 + 225)
Speed 40 ft., burrow 30 ft., fly 80 ft.

STR	DEX	CON	INT	WIS	CHA
30 (+10)	10 (+0)	29 (+9)	18 (+4)	15 (+2)	23 (+6)

Saving Throws Dexterity +7, Constitution +16, Wisdom +9, Charisma +13
Skills Perception +16, Stealth +7
Damage Immunities acid
Senses blindsight 60 ft., darkvision 120 ft., tremorsense 60 ft., passive Perception 26
Languages Common, Draconic, Terran
Challenge 23 (50,000 XP)

Special Traits

• Innate Spellcasting. The ancient dust dragon’s innate spellcasting ability is Constitution (spell save DC 24). It can cast the following spells, requiring no material components.
• 3/day: create or destroy water (destroy only)
• 2/day: stone shape
• 1/day: wall of stone
• Earthglide. The dragon can burrow through nonmagical, unworked earth and stone. While doing so, the dragon doesn’t disturb the material it moves through.
• Legendary Resistance (3/day). If the dragon fails a saving throw, it can choose to succeed instead.

Actions

• Multiattack. The dragon can use its Frightful Presence and make one Bite attack and two Claw attacks.
• Bite. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) piercing damage plus 14 (4d6) acid damage.
• Claw. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 17 (2d6 + 10) slashing damage.
• Tail. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage.
• Frightful Presence. Each creature of the dragon’s choice that is within 120 feet of the dragon and aware of it must succeed on a DC 21 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the dragon’s Frightful Presence for the next 24 hours.
• Sand Breath (recharge 5-6). The dragon exhales shards of stone and dust in a 90-foot cone. Each creature in that area must succeed on a DC 24 Dexterity saving throw, taking 85 (19d8) slashing damage on a failed saving throw, or half as much damage on a successful one.

Legendary Actions

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action can be used as a time and only at the end of another creature’s turn. The dragon regains spent legendary actions at the start of its turn.

• Detect. The dragon makes a Wisdom (Perception) check.
• Tail Attack. The dragon makes a Tail attack.
• Sandstorm (costs 2 actions). The ancient dust dragon creates a swirling maelstrom of sand and dust in a 120-foot radius centered on itself, which swirls until the end of the ancient dust dragon’s next turn. Creatures in the area must succeed on a DC 26 Constitution saving throw or be blinded for 1 minute. Creatures can repeat the saving throw at the end of each of its turns, ending the effect on a success. The ancient dust dragon is immune to the effects of its Sandstorm.
• Wing Attack (costs 2 actions). The dragon beats its wings. Each creature within 15 feet of the dragon must succeed on a DC 25 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.

Lair Actions

On initiative count 20 (losing initiative ties), the dragon takes a lair action to cause one of the following effects; the dragon can’t use the same effect two rounds in a row:

• The solid stone surrounding a point on the ground that the dragon can see within 120 feet of it turns into dust and sand in a 20-foot radius. The area is considered difficult terrain, and if a creature enters or begins their turn in the area it must make a DC 18 Strength saving throw or become restrained by the sudden quicksand. A restrained creature can use its action to attempt to free itself by making a DC 18 Strength check.
• The dust dragon chooses one creature it can see within 60 feet of it to begin to petrify, as if the dust dragon had cast the flesh to stone spell. The DC for this effect is 22.
• The dust dragon creates a column of swirling sand that is 10 feet in diameter and 40 feet high that continues churning until the start of the next initiative count 20. Creatures that enter or begin their turn in the area must make a DC 18 Dexterity saving throw, taking 17 (5d6) slashing damage on a failed saving throw, or half as much damage on a successful one.

Regional Effects

The region containing a legendary dust dragon’s lair is warped by the dragon’s presence, which creates one or more of the following effects:

• Creatures who succumb to the environment within 6 miles of the dust dragon’s lair often rise as dust ghouls under the dust dragon’s command.
• Oasis and water sources within 1 mile of the lair dry up and become sand and dust quickly.
• Dust mephits and other similar creatures find themselves at home within the area, and often attack intruders on sight.