This essay examines gender and ethnicity as performative categories in the ancient Greek novel. In the Arsake episode of the Aithiopika , Heliodorus questions classical Greek stereotypes of male versus female and Greek versus non-Greek by demonstrating the fluidity of markers for these categories. Thus, characters can act more or less “manly” or “Greek,” depending on their immediate situations and regardless of actual gender or ethnic identity. I argue that the novel presents gender as the more fixed of the two categories, but that every character operates within a wide range of behaviors, often contradicting the reader’s expectations.