Professor Quirrell - A stuttering and seemingly harmless man, and a professor of Defense against the Dark Arts at Hogwarts. Quirrell appears as nervous and squirrelly as his name suggests for most of the story. It is he, for example, who nearly faints when announcing the news that a troll is loose in the school. It turns out later, however, that Quirrell has faked his withdrawing meekness and is actually a cold-blooded conniver.