Fill this black mug with hot liquid and watch as the image magically appears. The word is out, Cobblepot is alive! This transforming mug features the villainous Oswald Cobblepot known as the Penguin from the popular FOX television series, Gotham. This mug transforms from black to a full color image of Cobblepott when filled with hot liquid. This 11 Oz mug is not microwave or dishwasher safe, hand wash only.