- Armor Class: 20 (Natural Armor)
- Hit Points: 333 (18d20 + 144)
- Speed: 40 ft., burrow 40 ft., fly 80 ft., swim 40 ft.
- Saving Throws: DEX +6, CON +14, WIS +7, CHA +8
- Skills: Perception +13, Stealth +6
- Damage Immunities: Cold
- Senses: Blindsight 60 ft., Darkvision 120 ft., Passive Perception 23
- Languages: Common, Draconic
- Challenge: 20 (25,000 XP)
- Proficiency Bonus: +6
Actions
- Multiattack: The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.
- Bite: Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 9 (2d8) cold damage.
- Claw: Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.
- Tail: Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage.
Legendary Actions
- Detect: The dragon makes a Wisdom (Perception) check.
- Tail Attack: The dragon makes a tail attack.
| STR | DEX | CON | INT | WIS | CHA |
| 26 (+8) | 10 (+0) | 26 (+8) | 10 (+0) | 13 (+1) | 14 (+2) |
Attributes
| AC | 20 (Natural Armor) |
| Alignment | Chaotic Evil |
| CHA | 14 |
| CON | 26 |
| Challenge Rating | 20 |
| DEX | 10 |
| HP | 333 (18d20+144) |
| INT | 10 |
| Immunities | Cold |
| Languages | Common, Draconic |
| Passive Perception | 23 |
| Roll 0 | Bite 1d20 + 14 2d10+8+2d8 |
| Roll 1 | Claw 1d20 + 14 2d6+8 |
| Roll 2 | Tail 1d20 + 14 2d8+8 |
| Roll 3 | Cold Breath 1d20 + 0 16d8 |
| STR | 26 |
| Saving Throws | Dex +6, Con +14, Wis +7, Cha +8 |
| Senses | Blindsight 60 Ft., Darkvision 120 Ft. |
| Size | Gargantuan |
| Skills | Perception +13, Stealth +6 |
| Speed | 40 ft., burrow 40 ft., fly 80 ft., swim 40 ft. |
| Type | dragon |
| WIS | 13 |