Adult Blue Dragon

Huge dragon, lawful evil

Armor Class 19 (natural armor)
Hit Points 225 (18d12 + 108)
Speed 40ft., burrow 30ft., fly 80ft.

STR 25 (+7) | DEX 10 (+0) | CON 23 (+6) | INT 16 (+3) | WIS 15 (+2) | CHA 19 (+4)

Saving Throws Dex +5, Con + 11, Wis +7, Cha +9
Skills Perception + 12, Stealth +5
Damage Immunities lightning
Senses blindsight 60ft., darkvision 120ft., passive Perception 22
Languages Common, Draconic
Challenge 16 (15,000 XP)

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

Parent ethnicities

• Young Blue Dragon

Diverged ethnicities

• Ancient Blue Dragon

Encompassed species

• Blue Dragon

Related Locations

• Blue Dragon's Lair

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: +12 to hit, reach 10ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 5 (1d10) lightning damage.
Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage.
Tail. Melee Weapon Attack: +12 to hit, reach 15ft., one target. Hit: 16 (2d8 + 7) 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 17 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 90-foot line that is 5 feet wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 66 (12d10) lightning damage on a failed save, or half as much damage on a successful one.

Legendary Actions

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.
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 10 feet of the dragon must succeed on a DC 20 Dexterity saving throw or take 14 (2d6 + 7) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.