In the Beren and Luthien story Sauron briefly takes the form of what is called
a "vampire," though as Aragorn Elessar mentions a few replies below, the
vampire here is not Dracula or Lestat, but something more like a vampire bat
creature. Sauron was something of a shape-shifter in his early career,
and he took on a variety of nasty forms. Maia demigods can take many
forms unless they expend their powers in other ways, such as making the One
Ring, or, like Morgoth, in fashioning Orcs, mountains, and generally corrupting
the fabric of
Middle-earth.
Still round the corner there may wait
A new road or a secret gate;
And though I oft have passed them by,
A day will come at last when I
Shall take the hidden paths that run
West of the Moon, East of the Sun.
