First of all to all of you... learn your tolkien and lotr properly... Yes Melkor (Morgoth) was of the Valar, and he could change physical forms, like all the valar, once he had tooken the silmarils, he went back with Ungolliath, and she was going to devour Melkor for the simlmaril, but he escaped or something like that, anyways once he came back, he transformed into a tall dark handsome malee extremly tall like.. 8-10 feet tall, and never changed forms again, and about that raider... when one of Feanor's son's came and challenged Morgoth to a duel, Morgoth had excepted, and he had slashed his hand, or his eye I think... anyways after that he was hurt so much he never set foot from his throne again, and the person who lost his hand was Barahir, when he went with luthien to retrive a silmaril, as luthien's father said he could not marry her until he had a silmaril in his hand, only as he left Angband, Melkor's hound had bit off his hand holding the silmaril, which caused the dog pain and sufering beyond belief... so the king went looking for the silmaril...
EDIT:
BTW, His armor was black, not gray and by black I mean void/charcoal black not some pansy ass gray...