By heaven, thou echo’st me,
As if there were some monster in thy thought
Too hideous to be shown.
– William Shakespeare
Othello, Act 3, Scene 3. Does Othello at some subconscious level realize that Iago is not what he appears to be, when he says this to Iago? The "monster" that Iago is thinking about and referred to by Othello is Othello’s jealousy. The irony is, however, that Iago is the monster, as he is trying to drive a wedge between Othello and Desdemona by playing on Othello’s jealousy.