Adult Blue Dragon

Huge dragon, Lawful Evil

Armor Class19 (natural armor)
Hit Points225 (18d12 + 108)
Speed40 ft., burrow 30 ft., fly 80 ft.
STRDEXCONINTWISCHA
25 (+7) 10 (+0) 23 (+6) 16 (+3) 15 (+2) 19 (+4)
Saving ThrowsCha +9, Con +11, Dex +5, Wis +7
SkillsPerception +12, Stealth +5
Damage Vulnerabilities—
Damage Resistances—
Damage Immunitieslightning
Condition Immunities—
Sensesblindsight 60 ft., darkvision 120 ft., passive Perception 22
LanguagesCommon, Draconic
Challenge16

Traits

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 Attack Roll: +12 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 7) piercing damage plus 5 (1d10) lightning damage.

Claw.

Melee Attack Roll: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage.

Tail.

Melee Attack Roll: +12 to hit, reach 15 ft., 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

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.