# Ancient Blue Dragon

*Gargantuan* *Dragon* *lawful evil*

- **Armor Class:** 22 (natural armor)
- **Hit Points:** 481 (26d20+208)
- **Speed:** walk 40 ft. burrow 40 ft. fly 80 ft.
- **Challenge Rating:** 23 (50,000 XP)
- **Source:** 5.1 SRD (2015 MM), page 282

| STR | DEX | CON | INT | WIS | CHA |
| --- | --- | --- | --- | --- | --- |
| 29 (+9) | 10 (+0) | 27 (+8) | 18 (+4) | 17 (+3) | 21 (+5) |

- **Saving Throws**: Dex +7, Con +15, Wis +10, Cha +12
- **Skills:** perception +17, stealth +7
- **Damage Immunities:** lightning
- **Senses:** blindsight 60 ft., darkvision 120 ft., passive Perception 27
- **Languages:** Common, Draconic

### Special Abilities

- **Legendary Resistance (3/Day):** If the dragon fails a saving throw, it can choose to succeed instead.

### 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: +16 to hit, reach 15 ft., one target. Hit: 20 (2d10 + 9) piercing damage plus 11 (2d10) lightning damage.
- **Claw:** Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 16 (2d6 + 9) slashing damage.
- **Tail:** Melee Weapon Attack: +16 to hit, reach 20 ft., one target. Hit: 18 (2d8 + 9) bludgeoning damage.
- **Frightful Presence:** Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 20 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.
- **Lightning Breath (Recharge 5-6):** The dragon exhales lightning in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 23 Dexterity saving throw, taking 88 (16d10) lightning damage on a failed save, or half as much damage on a successful one.

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The dragon regains spent legendary actions at the start of its turn.

### Legendary Actions

- **Detect:** The dragon makes a Wisdom (Perception) check.
- **Tail Attack:** The dragon makes a tail attack.
- **Wing Attack (Costs 2 Actions):** The dragon beats its wings. Each creature within 15 ft. of the dragon must succeed on a DC 24 Dexterity saving throw or take 16 (2d6 + 9) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.