In 1569 a broadsheet titled Ecclesia Militans was published in Ingolstadt by Alexanderv Weissenhorn. Written by Franciscan Johann Nas (1534–90), it incorporates a long poem and a complex image prepared under Nas’s direction and closely integrated with the text. The image and text present a number of figures from the book of Revelation, including the seven-headed beast and the whore of Babylon, and depict them alongside a parade of monstrous births born in Lutheran territories during the sixteenth century. This article examines Nas’s visual and textual sources, his aggressive appropriation of Lutheran models, and the stongly apocalyptic theme underlying his use of monstrous births as metaphors for the proliferation of Lutheran heresy. While the Ecclesia Militans was primarily a vehicle for Nas to attack his Lutheran opponents, it also incorporates an unexpected satire of his Jesuit rival Peter Canisius.