Living Shadow. While in dim light or darkness, the dragon has resistance to damage that isn't force, psychic, or radiant.

Shadow Stealth. While in dim light or darkness, the dragon can take the hide action as a bonus action.

Sunlight Sensitivity. While in dim light or darkness, the dragon has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 9 (1d10 + 4) piercing damage plus 3 (1d6) necrotic damage.

Shadow Breath (Recharge 5–6). The dragon exhales shadowy fire in a 15-foot cone. Each creature in that area must make a DC 13 Dexterity saving throw, taking 24 (7d6) necrotic damage on a failed save, or half as much damage on a successful one.