Gargantuan dragon, chaotic neutral
- Armor Class
- 22 (natural armor)
- Hit Points
- 370 (19d20 + 171)
- Speed
- fly 80 ft., 40 ft., climb 30 ft.
- Challenge
- 26 (90,000 XP)
- Saving Throws
- Con +17, Int +18, Wis +11
- Skills
- Arcana +18, Insight +11, Perception +11
- Damage Resistances
- cold; psychic; thunder
- Damage Immunities
- fire; lightning
- Condition Immunities
- charmed
- Senses
- blindsight 60 ft., darkvision 120 ft., passive Perception 21
- Languages
- Common, Draconic
Traits
If Niv-Mizzet fails a saving throw, he can choose to succeed instead.
Niv-Mizzet can maintain concentration on two different spells at the same time. In addition, he has advantage on saving throws to maintain concentration on spells.
Niv-Mizzet has advantage on saving throws against spells and other magical effects.
When Niv-Mizzet casts a spell that deals damage, he can change the spell's damage to cold, fire, force, lightning, or thunder.
Actions
Niv-Mizzet makes three attacks: one with his bite and two with his claws.
Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 18 (2d8 + 9) piercing damage plus 14 (4d6) fire damage.
Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 14 (2d4 + 9) slashing damage.
Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 16 (2d6 + 9) bludgeoning damage.
Niv-Mizzet exhales fire in a 90-foot cone. Each creature in that area must make a DC 25 Dexterity saving throw, taking 91 (26d6) fire damage on a failed save, or half as much damage on a successful one.
Legendary Actions
Niv-Mizzet casts one of his cantrips.
Niv-Mizzet makes a tail attack.
Niv-Mizzet beats his wings. Each creature within 15 feet of him must succeed on a DC 25 Dexterity saving throw or take 14 (2d4 + 9) bludgeoning damage and be knocked prone. Niv-Mizzet can then fly up to half his flying speed.
Niv-Mizzet regains a spell slot of 3rd level or lower.
Spellcasting
Niv-Mizzet is a 20th-level Izzet spellcaster. His spellcasting ability is Intelligence (spell save DC 26, +18 to hit with spell attacks). He has the following wizard spells prepared: