Hogwarts Portrait of the Fat Lady

PASSWORD? What better Hogwarts icon is there than the fat lady? protecting the Gryffindor common room and it's inhabitants for generations, passing the time between admitting students by  visiting other paintings or pursuing her musical talents in such ways as using her voice to break glass. If you don't have the password, you're not getting in chivalry or no chivalry! She is perhaps, one of the best paintings at Hogwarts.