This article challenges the largely humanist readings of Tove Jansson's Moomin books by drawing attention to the texts’ investment in questions of species, genealogy, and nonhuman life. The article relies on posthumanist and queer thought to expose the limits of humanist interpretations of Jansson's texts, thus complicating and expanding the scholarly understanding of how the Moomin characters challenge the bounds of gender, family, and subjectivity.