One more thing: nothing too human. I am willing to make exceptions. A nine foot tall giant is out. A cyclops... probably out too.
This bit puzzles me... vampires are very human in appearance, wolfmen are human most of the time, the Invisible Man is a human, albeit a crazy invisible one. This would also let out Dr. Jekyll/Mr. Hyde.
And here I was going to suggest Chick Young or Wilbur Grey types with a lot of Luck and Serendipity...