This paper focuses on Italo Calvino’s Fiabe Italiane (1956) and its relationship with posthumanism by analyzing a case of human–animal metamorphosis. Following Serenella Iovino’s (2014) insight that Calvino’s literary production can be seen as encapsulating some of the tenets of posthumanism, the paper first investigates Calvino’s conception of storytelling, arguing that in Fiabe Italiane folk and fairy tales can be compared to Calvino’s investigation of variants, leading to the development of a post-anthropocentric type of narrative. Employing Gilles Deleuze’s concept of becoming, it then discusses metamorphosis as a form of becoming–animal, challenging the idea of an ontological categorization of humans and animals. Ultimately, the paper proposes a posthumanist reading of “Body-without-Soul” by highlighting how becoming–animal allows a rearrangement of the hierarchy between humans and the non-human world and promotes behaviors based on trust and codependence. Based on these findings, one can hypothesize that the magical realm of fairy tales can already be regarded as a place of experimentation where an alternative reality, as described by posthumanist theories, can be imagined and possibly actualized.