The Mouth of Sauron in Barad-dur

During the Dark Years of The Third Age of Middle-earth, he was no Ringwraith but a living man ... his name is remembered in no tale, for he himself had forgotten it.
Despite his high status being similar to a Nazgûl, the Mouth was a living Man, whose early history was largely forgotten. He was a Black Númenórean, Men who worshiped Sauron and made dwellings in Middle-earth during his domination.[3] The Mouth later entered into the direct "service of the Dark Tower when it first rose again"[3] in TA 2951.
The Mouth's cunning allowed him to be increasingly favored by the Dark Lord, and he learned much of Sauron's mind.[3] He was taught great sorcery and, being crueler than any Orc, rose to prominence as the Lieutenant of the Tower of Barad-dûr.[3] As the Mouth of Sauron, he was one of the few servants of Mordor who communicated directly with the Dark Lord. Though the Dark Lord banned his subjects from using his Elvish name,[4] The Mouth could use the name for some untold exception,[5] possibly for better communication with the Free Peoples of the World. He also rode upon a large black steed that may have been a horse, though it was hideous in appearance.[3] The creature's head looked skull-like; more dead than living. There was a burning flame in its eye sockets and nostrils.[3]