The clip, "Benedict Cumberbatch and the Sign of Four (or is it Three?)" has been viewed nearly 200,000 since it was posted on YouTube Tuesday morning.
It shows Cumberbatch enlisting the help of the Count after Murray challenges him to determine whether he has more apples or oranges.
Murray tells Cumberbatch he is his arch-nemesis, Murray-arty, a nod to the villain Moriarty on the actor's wildly popular drama series "Sherlock." Cumberbatch plays iconic sleuth Sherlock Holmes on the show, which wrapped its third season Sunday night.