Sluagh Swarm

Some say the sluagh are fey turned by vampires, while others say they are the evil souls of violent men, who cannot rest and return to kill. Still others claim they are the souls of devilbound gnomes who committed suicide. All agree that they are loathsome by nature.
Cowards Alone. These tiny, malevolent fey dwell in darkness. Alone they are cowards, but they are rarely encountered alone. They are most active during the winter, especially during winter’s long nights. They usually speak to their victims as they attack, but those shouts are little more than whispers to the ears of their prey.
Chilling Touch. Sluagh feed by using their chilling touch. They devour small animals if nothing more appetizing is available. Their victims are easy to identify; their skin is unnaturally cold, and their features are frozen in fear.
Swarms of sluagh serve hags, devils, trollkin, and evil fey who know the blood rituals to summon and direct them. Shadow fey and drow send them against other elves, often targeting the defenders of elven settlements, or their spouses and children.
Legless Flocks. Sluagh are tiny, gaunt humanoid creatures the size of a weasel. They have no legs; instead their torso tapers off in a disquieting way. Though they can fly, they can also pull themselves quickly across the ground with their arms. They are always draped in black, though their actual skin and hair are pale white. They have sharp claws and fangs, and their eyes are entirely black. In masses, they somewhat resemble a flock of strange birds.