Bibliothèque nationale de France (1960), Public domain, via Wikimedia Commons
(left) a dubiously legal pdf I found online of Rosencrantz and Guildenstern are Dead by Tom Stoppard. This absurdist comedy elevates these minor characters into the main focus of an existential drama.
Rosencrantz is a character who is able to keep up with Hamlet's rhetorical turns at first, though he does eventually get outmaneuvered and confesses to being sent for by the king.
As one of Claudius's courtiers, Osric is not in Hamlet's good graces. In the Folger's edition, Hamlet reveals his fallible nature by getting him to agree that the weather is both cold and hot within the span of a single sentence. His quick switching brings to mind the sun and moon scene between Petruchio and Katherine in The Taming of the Shrew:
Despite his waffling, Osric is rendered the sort of referee to the duel between Hamlet and Laertes. He is one of the few survivors of the final scene's massacre.
Rosencrantz and Osric are both educated but often foolish figures who are outsmarted by those around them. Neither have access to the full machinations of the other characters, and while Osric escapes with his life, Rosencrantz is not so lucky. Taken together, they are two sides of the same coin: focused on self-advancement and willing to be slippery in order to get their way.