Nightmare Beast. The Void Dragon becomes invisible while in darkness until they attack or make an attack, or if the light otherwise brightens. While in dim light creatures have disadvantage on perception checks on detecting it.

Bite. Melee Weapon Attack: +2 to hit, reach 3 ft., 1 target. Hit: 6 (1d6 + 4) piercing damage. 

Claws. Melee Weapon Attack: +2 to hit, reach 5 ft., 1 target. Hit: 10 (2d6 + 4) slashing damage. 

Tail. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit:  6 (1d6 + 4) bludgeoning damage.

Void Breath (Recharge 5-6). Ranged Weapon Attack: +1 to hit, range 5/20 ft., a 3 ft sphere in range. Hit: 18 (5d6 + 5) force damage and any creature within 10 ft of the targeted point must make a DC 12 DEX saving throw or be pulled 10 ft into the point.