Has the Joker been revealed? Image: Giphy A huge, insane, unbelievable and mind-blowing "Gotham" fan theory is making its way around the Internet, but the craziest thing of all is that it kind of makes sense. Warning: "Gotham" spoilers below. Originally posted on Reddit, the theory suggest that the show's Penguin, Oswald Cobblepot, is actually the Joker. The Theory Redditor Cohencide first points out that the Cobblepot on the show is not the traditional Penguin we've grown accustom to in the "Batman" franchise.