Droggoth in the Blue Mountains
Droggoth (S. "Thrall-enemy" or Or. "Thrall-master") was a winged fire-drake that as known as "the Dragonlord". He was considered to be the next greatest dragon in the Withered Heath. He was black scaled and unlike most dragons, he wore some armor over his scales. Droggoth was said to be able to unite dragons to fight for him—but eventually he flew to Ered Luin where he met his doom, slain by elves and dwarves.
(The Lord of the Rings: The Battle for Middle-earth II)
Notes[]
Original form: Drogoth = Droggoth
Drogoth could be an actual Goldogrin name meaning "track-enemy" or "rut-enemy", which wouldn't make much sense, more likely it could be interpreted as "Droggoth", Drog being a Goldogrin term for thrall, which could perhaps be interpreted as a rare Sindarin dialectial form or a Nandorin substrate. Drogoth also could be from an unknown orcish dialect.