Valaraukar

Valaraukar was a Quenya name formed from words vala, 'power' and rauko, 'demon'. The Valaraukar were the monstrous Maiar that Melkor took into his service, to become some of his most feared and dangerous servants. In Middle-earth, their name was changed from the Quenya form Valaraukar to the more familiar Sindarin form: Balrogs.