Ancient Lunar Dragon

(Boo's Astral Menagerie)

Gargantuan dragon, Neutral Evil

Armor Class18 (natural armor)
Hit Points297 (17d20 + 119)
Speed40 ft., burrow 20 ft., fly 80 ft.
STRDEXCONINTWISCHA
27 (+8) 12 (+1) 24 (+7) 12 (+1) 15 (+2) 17 (+3)
Saving ThrowsCon +13, Wis +8
SkillsPerception +14, Stealth +13
Damage Vulnerabilities—
Damage Resistances—
Damage Immunitiescold
Condition Immunities—
Sensesdarkvision 240 ft., passive Perception 24
LanguagesDraconic
Challenge19

Traits

Legendary Resistance (3/Day).

If the dragon fails a saving throw, it can choose to succeed instead.

Tunneler.

The dragon can burrow through solid rock at half its burrowing speed and leaves a 20-foot-diameter tunnel in its wake.

Unusual Nature.

The dragon doesn't require air.

Actions

Multiattack.

The dragon makes one Bite attack and two Claw attacks.

Bite.

Melee Attack Roll: +14 to hit, reach 15 ft., one target. Hit: 15 (2d6 + 8) piercing damage plus 7 (2d6) cold damage.

Claw.

Melee Attack Roll: +14 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.

Tail.

Melee Attack Roll: +14 to hit, reach 20 ft., one target. Hit: 15 (2d6 + 8) bludgeoning damage.

Cold Breath (Recharge 5-6).

The dragon exhales a blast of frost in a 90-foot cone. Each creature in the cone must make a DC 21 Constitution saving throw. On a failed save, the creature takes 36 (8d8) cold damage, and its speed is reduced to 0 until the end of its next turn. On a successful save, the creature takes half as much damage, and its speed isn't reduced.

Legendary Actions

Tail Attack.

The dragon makes one Tail attack.

Treacherous Ice.

Magical ice covers the ground in a 20-foot radius centered on a point the dragon can see within 120 feet of itself. The ice, which is difficult terrain for all creatures except lunar dragons, lasts for 10 minutes or until the dragon uses this legendary action again.

Wing Attack (Costs 2 Actions).

The dragon beats its wings. Each creature within 15 feet of the dragon must succeed on a DC 21 Dexterity saving throw or take 12 (1d8 + 8) bludgeoning damage and be knocked prone. The dragon can then fly up to half its speed without provoking opportunity attacks.