Wretched Pack Tactics. The Wretched has advantage on an attack roll against a creature if at least one of the Wretched's allies is within 5 feet of the creature and the ally isn't incapacitated. The Wretched otherwise has disadvantage on attack rolls.
Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit:6 (1d10 + 1) piercing damage, and the Wretched attaches to the target. While attached, the Wretched can't attack, and at the start of each of the Wretched's turns, the target takes 6 (1d10 + 1) necrotic damage.
The attached Wretched moves with the target whenever the target moves, requiring none of the Wretched's movement. The Wretched can detach itself by spending 5 feet of its movement on its turn. A creature, including the target, can use its action to detach a Wretched.
The Shadowfell's pervasive melancholy sometimes gives rise to strange incarnations of the plane's bleak nature. The sorrowsworn embody the forms of suffering that are inherent to the shadowy landscape, and they visit horror on those who stumble into their midst.