Ancient Blue Dragon
Gargantuan Dragon (Chromatic), Lawful Evil
AC 22 Initiative +14 (24)
HP 481 (26d20 + 208)
Speed 40 ft., Burrow 40 ft., Fly 80 ft.
Ability Scores
STR 29 (+9) Save +9 DEX 10 (+0) Save +7 CON 27 (+8) Save +8
INT 18 (+4) Save +4 WIS 17 (+3) Save +10 CHA 25 (+7) Save +7
Skills Perception +17, Stealth +7
Immunities Lightning
Senses Blindsight 60 ft., Darkvision 120 ft.; Passive Perception 27
Languages Common, Draconic
CR 23 (XP 50,000, or 62,000 in lair; PB +7)
Traits
Legendary Resistance (4/Day, or 5/Day in Lair). If the dragon fails a saving throw, it can choose to succeed instead.
Actions
Multiattack. The dragon makes three Rend attacks. It can replace one attack with a use of Spellcasting to cast Shatter (3rd level).
Rend. Melee Attack Roll: +16, reach 15 ft. Hit: 18 (2d8 + 9) Slashing damage plus 11 (2d10) Lightning damage.
Lightning Breath (Recharge 5–6). Dexterity Saving Throw: DC 23. Each creature in a 120-foot-long, 10-foot-wide line must make the save. Failure: 88 (16d10) Lightning damage. Success: Half damage.
Spellcasting. The dragon casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 22):
At Will: Detect Magic, Invisibility, Mage Hand, Shatter (3rd level)
1/Day Each: Scrying, Sending
Legendary Actions
Legendary Action Uses: 3 (4 in Lair). Immediately after another creature’s turn, the dragon can expend a use to take one of the following actions. The dragon regains all expended uses at the start of each of its turns.
- Cloaked Flight. The dragon uses Spellcasting to cast Invisibility on itself, and it can fly up to half its Fly Speed. The dragon can’t take this action again until the start of its next turn.
- Sonic Boom. The dragon uses Spellcasting to cast Shatter (3rd level). The dragon can’t take this action again until the start of its next turn.
- Tail Swipe. The dragon makes one Rend attack.
