Accursed Death. When the dragon dies, it exudes a cloud of sickening, accursed gas. Each creature within 20 ft. of the dragon must succeed on a DC 15 Constitution saving throw or become poisoned 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. However, a creature that fails two of these saving throws becomes cursed. A creature cursed in this way takes 10 (3d6) necrotic damage and can’t regain hit points, and the creature’s hit point maximum is reduced by an amount equal to the necrotic damage taken. Every 24 hours, the cursed creature takes 10 (3d6) necrotic damage with similar reduction to the creature’s hit point maximum. If the curse reduces the target’s hit point maximum to 0, the target dies.

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

Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 13 (2d8 + 4) piercing damage and 5 (2d4) necrotic damage.

Claw. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 (2d4 + 4) slashing damage and 2 (1d4) poison damage.

Swarm Breath (Recharge 5–6). The dragon exhales a 30-foot cone of poisonous insects and vile gas. Each creature in that area must make a DC 15 Constitution saving throw, taking 14 (4d6) piercing damage and 28 (8d6) poison damage on a failed save, or half as much damage on a successful one.