Multiattack

The skull drake makes two bite attacks.

Bite

Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 10 (2d6 + 3) piercing damage.

Necrotic Breath (Recharge 6)

The skull drake exhales a 15-foot cone of noxious, black gas. Each creature in the area must make a DC 13 Constitution saving throw, taking 14 (4d6) necrotic damage on a failed save, or half as much damage on a successful one. A creature reduced to 0 hp by this damage dies.