Since the Middle Ages, Christian art has known grotesque mask forms primarily for the defense and banishment of evil powers. From around the 15th century, however, the grotesque distortion of the human face is employed to expose church and state dignitaries in the political, social, and theological conflicts of the time. In this context, the mask serves not to conceal but to reveal the supposedly evil in the form of the opponent. The focus of this work is primarily on double-headed medals, in which popes and cardinals are transformed into devils and fools through inversion. The investigation centers on motifs of the ugly and their counter-images of the holy and the perfect. Within the framework of iconographic, religious-historical, and aesthetic questions, original writings from the 15th and 16th centuries are related to the monuments in order to highlight the difference between theological aspects and the humanistically shaped understanding of art. Works by Leonardo da Vinci, Dürer, Grünewald, and especially the imagery of Bosch are used as representative examples of artistic creation in Italy, Germany, and the Netherlands. In the understanding of art during the Mannerism period, the pleasure in the misshapen and the fantastic aspect of the ugly increasingly play the role of the value-free curious, so that the double-headed medals should not only be viewed in terms of the moral aspect of depicting evil but also in light of their playful appeal.