Troilus and Cressida
Okay. We know the Prologue isn't exactly a "character" but this figure is a soldier dressed in armor who appears on stage at the beginning of the play. It's the Prologue's job to give us the 411 on the play's setting and conflict (that would be the Trojan War). Unlike the Prologue of Romeo and Juliet, this Prologue doesn't have a crystal ball and can't predict the future. He goes out of his way to tell us that he is "a prologue arm'd, but not in confidence / of author's pen or actor's voice" (Prologue, 24-25). In other words, this Prologue is not omniscient. But, that doesn't really matter because anybody who's familiar with the story of the Trojan War or has heard the love story of Troilus and Cressida already knows how things are going to turn out, right?