Yes, I agree with that completely - from the text of course: 'And Sauron immediately took the form of a vampire , great as a dark cloud across the moon, and he fled, dripping blood from his throat upon the trees (where did the blood come from ? Huan?) and came to Taur-Nu-Fuin, and dwelt there, filling it with terror." Luthien: '...and the bat-fell of Thuringwethel. She was the messenger of Sauron, and was wont to fly in vampire's form to Angband (hence a shape-shifter also); and her great fingered wings were barbed at each joint's end with an iron claw....'