Multiattack.

The dragon makes one Bite attack and two Claw attacks.

Bite.

Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 15 (2d10 + 4) piercing damage plus 5 (1d10) radiant damage.

Claw.

Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.

Breath Weapon (Recharge 5–6).

The dragon uses one of the following breath weapons:

Dream Breath. The dragon exhales mist in a 90-foot cone. Each creature in that area must succeed on a DC 14 Constitution saving throw or fall unconscious for 10 minutes. This effect ends for a creature if the creature takes damage or someone uses an action to wake it.
Moonlight Breath. The dragon exhales a beam of moonlight in a 60-foot line that is 5 feet wide. Each creature in that area must make a DC 14 Dexterity saving throw, taking 38 (7d10) radiant damage on a failed save, or half as much damage on a successful one.

Spellcasting.

The dragon casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 15):

Young Moonstone Dragon