Ancient White Dragon

Gargantuan Dragon (Chromatic), Chaotic Evil

AC: 20

Initiative: +12 (22)

HP: 333 (18d20 + 144)

Speed: 40 ft., burrow 40 ft., fly 80 ft., swim 40 ft.

STR: 26 (+8)
DEX: 10 (+0)
CON: 26 (+8)
INT: 10 (+0)
WIS: 13 (+1)
CHA: 18 (+4)

Saving Throws: Dex +6, Wis +7

Skills: Perception +13, Stealth +6

Immunities: cold

Senses: Blindsight 60 ft., Darkvision 120 ft., Passive Perception 23

Languages: Common, Draconic

CR: 20 (XP 25,000, or 33,000 in lair; PB +6)

Habitat: Arctic

Treasure: Arcana

Ice Walk.

The dragon can move across and climb icy surfaces without needing to make an ability check. Additionally, Difficult Terrain composed of ice or snow doesn't cost it extra movement.

Legendary Resistance (4/Day, or 5/Day in Lair).

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

Frightful Presence.

The dragon casts Fear, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 18). The dragon can't take this action again until the start of its next turn.

Actions

Multiattack.

The dragon makes three Rend attacks.

Rend.

Melee Attack Roll: +14, reach 15 ft. Hit: 17 (2d8 + 8) Slashing damage plus 7 (2d6) Cold damage.

Cold Breath (Recharge 5-6).

Constitution Saving Throw: DC 22, each creature in a 90-foot Cone. Failure: 63 (14d8) Cold damage. Success: Half damage.

Legendary Actions

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature's turn, this creature can expend a use to take one of the following actions; it regains all expended uses at the start of each of its turns.

Freezing Burst.

Constitution Saving Throw: DC 20, each creature in a 30-foot-radius Sphere centered on a point the dragon can see within 120 feet. Failure: 14 (4d6) Cold damage, and the target's Speed is 0 until the end of the target's next turn. Failure or Success: The dragon can't take this action again until the start of its next turn.

Pounce.

The dragon moves up to half its Speed, and it makes one Rend attack.

Regional Effects

The region containing an adult or ancient white dragon's lair is affected by its presence, creating the following effects:

Frigid Cold.
The area within 1 mile of the lair is an area of extreme cold. Any water in that area is frigid water. See the Dungeon Master's Guide for rules on extreme cold and frigid water.
Glacial Gloom.
The area within 1 mile of the lair is Lightly Obscured by chilly fog. Whenever a creature other than the dragon or one of its allies finishes a Long Rest in that area, that creature must succeed on a DC 15 Constitution saving throw or have its Speed reduced by 10 feet for 1 hour.

If the dragon dies or moves its lair elsewhere, these effects end immediately.

Find this creature in the encounter builder

Source: Monster Manual (2025), p. 330 - Licenses and attribution