At the climax of Antony and Cleopatra, when Cleopatra is about to kill herself, Shakespeare introduces a Clown. The clown, or fool, or jester in Shakespeare is most often the truth-teller, the character who can tell painful truths to the monarch with impunity. He also seems to be the voice of the dramatist commenting on the action.
I personally love the clowning of the rood mechanicals in A Midsummer Night's Dream.