Studies in the field of literary anti-Semitism have long ignored literary characters who take on a false ‘Jewish’ identity or who misleadingly pass for ‘Jews’. This article stresses that such characters are, however, of great value for the discipline. It shows which characteristics lead to their being ‘recognized’ as ‘Jews’, and what this implies regarding defining categories, cultural settings and the historic discourse before and after the Shoah. The characters’ name-changes suggest that ‘onomastic denunciation’ was still possible, their physical modifications display the topic’s entanglement with constructions of the ‘Jewish body’ in cultural and medical history that continue to be virulent even after 1945. But what are the functions of these characters within the text? What is the effect of the shifts in identity, typecasting and attributions? Are anti-Semitic stereotypes of ‘the Jew’ in literature thus perpetuated or are they rather undermined?