Amphibious. The dragon can breathe air and water.

Multiattack. The dragon makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage.

Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 4) slashing damage.

Breath Weapons (Recharge 5–6). The dragon uses one of the following breath weapons.

Radiant Breath. The dragon exhales light in a 30-foot cone. Each creature that is not an ally in that area must make a DC 17 Dexterity saving throw, taking 55 (10d10) radiant damage on a failed save, or half as much damage on a successful one. Any ally will be healed for the amount of damaged rolled.

Summoning Breath. The dragon uses pheromones in its breath to summon Vaporous Serpents. The dragon summons 1d2 Serpents, they appear within 60-ft of the dragon, acts as an ally to the dragon, and remains for 1-minute, until it dies or until the Dragon dismisses it as a Bonus Action.