Multiattack

The drake makes one bite attack and one tail slap attack.

Bite

Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 22 (3d10 + 6) piercing damage.

Tail Slap

Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 19 (3d8 + 6) bludgeoning damage.

Stygian Breath (Recharge 5-6)

The elder shadow drake exhales a ball of black liquid that travels up to 60 feet before exploding into a cloud of frigid black mist with a 20-foot radius. Each creature in that sphere takes 42 (12d6) cold damage, or half damage with a successful DC 15 Constitution saving throw. Within the area of effect, the mist snuffs out nonmagical light sources and dispels magical light of 1st level or lower.