[Mattius]

Here is a reference i found from a book i own.

Whether it was from bird or beast that Melkor bred the evil bloodsucking Bat of Middle-earth, not tale tells. But in the first Age of the Sun, it is told how, in this winged form- made large and armed with talons of steel- Vampire spirits came into service of Melkor the Dark Enemy.

In the Quest of the Silmaril, Thuringwethil, the "woman of secret shadow" was a mighty Vampire and was the chief messenger to travel between Angband and Tol-in-Goauroth, where Sauron ruled the Werewolf legions. When Tol-in-Gaurhoth fell, Sauron himself took on Vampire shape and fled. Once the sorcerous power of Sauron was broken, many evil enchantments were also shattered. The shaping cloak that gave Thuringwethil the power to take Bat-shape fell from her, and the Vampire's dead spirit fell.