The origins of selected instances of metamorphosis in Germanic literature are traced from their roots in Ovid’s Metamorphoses, grouped roughly on an ‘ascending evolutionary scale’ (invertebrates, birds, animals, and mermaids). Whilst a broad range of mythological, legendary, fairytale and folktale traditions have played an appreciable part, Ovid’s Metamorphoses is still an important comparative analysis and reference point for nineteenth- and twentieth-century German-language narratives of transformations. Metamorphosis is most often used as an index of crisis: an existential crisis of the subject or a crisis in a society’s moral, social or cultural values. Specifically selected texts for analysis include Jeremias Gotthelf’s Die schwarze Spinne (1842) with the terrifying metamorphoses of Christine into a black spider, the metamorphosis of Gregor Samsa in Kafka’s Die Verwandlung (1915), ambiguous metamorphoses in E. T. A. Hoffmann’s Der goldne Topf (1814), Hermann Hesse’s Piktors Verwandlungen (1925), Der Steppenwolf (1927) and Christoph Ransmayr’s Die letzte Welt (1988). Other mythical metamorphoses are examined in texts by Bachmann, Fouqué, Fontane, Goethe, Nietzsche, Nelly Sachs, Thomas Mann and Wagner, and these and many others confirm that metamorphosis is used historically, scientifically, for religious purposes; to highlight identity, sexuality, a dream state, or for metaphoric, metonymic or allegorical reasons.