This article explores the connections between Nietzsche's Also Sprach Zarathustra and Tove Jansson and the world of the Moomins. It begins with a short summary of the impact of Nietzsche in the Nordic countries and of his most important book, focusing on passages that are of particular relevance for the analyses that follow. It then proceeds to explore its meaning and significance for Jansson in three sections. The first concerns Atos Wirtanen, the writer and politician with whom she lived for ten years, and who encouraged her to publish her first book, while he himself was completing a book on Nietzsche. In the second section, the article analyzes an early semi-autobiographical literary experiment from the Jansson family archive that displays her as a passionate reader of Nietzsche long before her meeting with Wirtanen. In the third and last section, the framework of the Zarathustra narrative is used to interpret some of the figures and scenes from the Moomin books.