European puppet theaters were deeply involved during World War I, which gave them an opportunity for demonstrating their social utility as a tool of moral and civic education for children. Behind the lines, they took part in the wartime effort in the context of a “total war” leading to a full-time mobilization of the civilian populations. This mobilization implied many transformations of popular repertoires: the regional characters Guignol and Kasperl had to embody national identities; their traditional laziness, insolence, and reluctance to commands disappeared, so they could become exemplary soldiers; while the representation of these new heroes gave way to some complexity, enemies were more heavily caricatured. In this context, very different options can nonetheless appear. In German plays, the war-time repertoire for Kasperl is mainly intended to make young audiences laugh at the conflict, and it therefore keeps farcical traits. In Paris, Gaston Cony’s Guignol de la Guerre, moralizing and edifying, tries to give a somehow realistic image of the soldiers’ everyday life. But they all agree in ascribing a radical otherness to their enemies, who are racialized or animalized, when they are not denied their humanity. Based upon a comparison between German or Austrian (Oberndorfer, Renker, Rendlös, Voelckers) and French (Cony, Flesky du Rieux) puppet repertoires composed during or in the aftermath of WWI, this paper examines how these productions took part in the “bourrage de crânes” (brainwashing) of public opinions, instilling hatred of other nations in the minds of the youngest.