Vampire's Thrall is a creature that is the result of the power, Vampire's Servant, in The Elder Scrolls V: Skyrim.
Characteristics
They are beings that are forcibly under the control of a Vampire, and thus possess no free will of their own. They will attack the Dragonborn on sight. Be wary, as finding a Thrall ensures that a Vampire will be nearby. It is believed that they are former adventurers, exploring the caves.