AC 19 (natural armor)
HP 253 (22d12 + 110; bloodied 126)
Speed 40 ft., fly 80 ft., swim 40 ft.
Proficiency +6; Maneuver DC 20
Saving Throws Dex +8, Con +11, Wis +7, Cha +9
Skills History +8, Perception +7 (+1d6), Stealth +8
Damage Immunities acid, necrotic, poison
Condition Immunities charmed , fatigued , frightened , paralyzed , poisoned
Senses blindsight 60 ft., darkvision 120 ft., passive Perception 20
Languages Common, Draconic
Ambusher. When submerged in water, the dragon has advantage on Stealth checks. If the dragon hits a creature that can’t see it with its bite, it can deal piercing damage and grapple the target simultaneously.
Innate Spellcasting. The dragon’s spellcasting ability is Charisma (save DC 17). It can innately cast the following spells, requiring no material components.
3/day each: animate dead , fog cloud , legend lore , pass without trace , speak with dead
Legendary Resistance (3/Day). When the dragon fails a saving throw , it can choose to succeed instead. When it does, it loses its Undead Telepathy trait until the end of its next turn. Until the end of its next turn, undead creatures under its control are incapacitated .
Ruthless (1/Round). After scoring a critical hit on its turn, the dragon can immediately make one claw attack.
Rejuvenation. If it has a soul vessel, a destroyed dragon lich gains a new body in 1d10 days, regaining all its hit points. The new body forms within 10 feet of the soul vessel.
Turn Resistance. The dragon has advantage on saving throws against any effect that turns undead.
Undead Nature. The dragon doesn’t require air, sustenance, or sleep.
Undead Telepathy. The dragon lich can communicate telepathically with undead creatures within 120 feet.
ACTIONS
Multiattack. The dragon attacks once with its bite and twice with its claws. In place of its bite attack, it can use Acid Spit.
Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 22 (3d10 + 6) piercing damage plus 4 (1d8) acid damage. Instead of dealing piercing damage, the dragon can grapple the target (escape DC 20), and a Large or smaller creature grappled in this way is restrained . While grappling a creature, the dragon can’t bite or use Acid Spit against another target.
Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 19 (3d8 + 6) slashing damage.
Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 15 (2d8 + 6) bludgeoning damage, and the dragon pushes the target 10 feet away.
Acid Spit. The dragon targets a creature within 60 feet, forcing it to make a DC 19 Dexterity saving throw . The creature takes 22 (4d10) acid damage on a failure or half damage on a success. A creature that fails the save also takes 5 (1d10) ongoing acid damage. A creature can use an action to end the ongoing damage.
Acid Breath (Recharge 5–6). The dragon exhales sizzling acid or necrotic energy in a 60-foot-long, 5-foot-wide line. Each creature in that area makes a DC 19 Dexterity saving throw , taking 31 (7d8) acid damage and 31 (7d8) necrotic damage on a failed save or half damage on a success. A creature that fails the save is blinded until the end of its next turn.
REACTIONS
Tail Attack. When a creature the dragon can see within 10 feet hits the dragon with a melee attack, the dragon makes a tail attack against it.
LEGENDARY ACTIONS
The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. It regains spent legendary actions at the start of its turn.
Darkness. The dragon creates a 20-foot-radius sphere of magical darkness originating from a point it can see within 120 feet. Darkvision can’t penetrate this darkness. The darkness lasts for 1 minute or until the dragon uses this action again.
Roar. Each creature of the dragon’s choice within 120 feet that can hear it makes a DC 17 Charisma saving throw . On a failure, it is frightened for 1 minute. A creature repeats the saving throw at the end of its turns, ending the effect on itself on a success. When it succeeds on a saving throw or the effect ends for it, it is immune to Roar for 24 hours.
Wing Attack. The dragon beats its wings. Each creature within 15 feet makes a DC 20 Dexterity saving throw . On a failure, it is pushed 10 feet away and knocked prone . The dragon can then fly up to half its fly speed.
Combat
While individual dragons have their own personalities and tactics, most rely heavily on their breath weapons. They use them whenever they can, preferably from maximum distance and while flying above their enemies.
When fighting in the open, dragons often circle above their enemies as they wait for their breath weapons to recharge. They only close to melee if their enemies deal significant damage with ranged attacks, or if they can savage an enemy cut off from its allies. Once bloodied , dragons become more aggressive, attacking with bite and claws when their breath weapons aren’t available.
If a dragon is protecting its lair, it utilizes lair features, traps, allies, and architecture such as escape tunnels to keep up a hit-and-run fight, reappearing only when it has a fully-recharged breath weapon. If the dragon is forced into melee combat, it uses its bite and claws against a single foe. If it has legendary actions like Roar and Wing Attack, it uses them to disperse its other enemies.
If reduced to less than one-fourth its hit points while fighting in the open, a dragon flies away. However, it fights to the death to defend its lair, unless it can regain the upper hand through tricks or bargains.
Some dragons seek to defy death, becoming undead dragon liches. Such a dragon channels its inherent magical nature into an arcane spark that grants it a semblance of life beyond death. Scales and flesh slough off the dragon lich, eventually leaving nothing but a skeletal dragon brooding over moldering treasure.
In order to become a dragon lich, a dragon must imbue its spirit into a soul vessel. The vessel is usually some treasured item from the dragon’s hoard, such as a particularly valuable gem or piece of jewelry. The dragon can’t bear to be apart from its soul vessel and keeps it close among its hoard. The only way to permanently defeat a dragon lich is to destroy both the dragon and the soul vessel.