In this dissertation, I define and theorize a novel category of transmedial mimetic activity, “actualized mimesis,” and apply it to the study of ancient Greek and Roman culture. Actualized mimesis occurs when an independent process of life (a process, which is not normally mimetic and has its own purpose) becomes the vehicle for a dynamic representation. All actualized mimeseis are united by two characteristics, which lend the category its coherence and interest: (1) the metaleptic character of the resulting composite process, which retains its original identity while also serving as a representation and (2) the uncanny fact that, because the enactment of an actualized mimesis depends upon the enactment of an unrelated process, it can appear to occur out of nowhere and even contrary to the intentions of its agent, hijacking elements of reality as unwilling actors. An actualized mimesis is catalyzed by a functional object when a predictable action or actions involved in its use-process serves as the vehicle for a representation. The majority of catalysts for actualized mimesis surviving from the ancient Mediterranean fall into the categories of drinking and lighting equipment. Via a multitude of close readings of objects and texts, I reveal that vessels and lamps designed to catalyze actualized mimesis were closely associated with gods of transformation and duality such as Dionysus and Eros. Via actualized mimesis, functional objects figured independent processes of the symposium, for example, as representations of miracles attributed to Dionysus in mythology. Others generated automatic parodies, taught lessons or interactively materialized complex metaphors related to the dynamics of arousal and intoxication. Because these objects transform their processes of use into masked processes, which reveal something intrinsic about the actions they obscure, they act as Dionysian revelatory masks that roast, mystify, titillate or otherwise interact with their users in laughter and discussion-provoking ways. Actualized mimesis, furthermore, allows artists to materially and dynamically represent divinities in their dual character, as abstract forces of nature and anthropomorphic characters of myth. Actualized mimesis is used to lend material existence the flexibility and polyvalence of thought and the expressive capacity of figurative language.