"Oz" is a powerful wizard who is initially believed to be the ruler of the Land of Oz. In Chapter 15, it is revealed that the "Great and Terrible Wizard of Oz" is actually a charlatan from Omaha, Nebraska, who used his theatrical skills to create an image of a powerful wizard in order to gain control of the kingdom. In Chapter 16, it is revealed that his real name is Oscar Diggs, and he has been an illusionist, circus worker and a medicine man before tricking the people of Oz into believing he was a wizard. However, the revelation of his true identity does not diminish his role as a leader and helper to the people of Oz.