When he is being himself, with facial hair, etc., he isn’t creepy at all. However, he plays creepy very well. Truman Capote was a creepy little git, and Hoffman recreated that beautifully. Many of his other roles also call for him to be equally creepy, clammy, intelligent, spacey or just plain weird. He does it so well that those of us who haven’t met him personally are convinced that he isn’t acting but just being himself in front of the camera (as so many current “actors” do).