ABSTRACT This article investigates what is at stake in decolonising the study of conspiracy theories online. It challenges the confidence with which conspiracy theories are often dismissed as aberrations and negative externalities of digital ecosystems. Without reifying conspiracy theories, we identify as problematic how alternative forms of knowledge production are dismissed and colonial tropes reproduced. Contributing to conversations around ‘decolonising the internet’, we offer additional and sharper tools to understand the role and implications of conspiracy theorising for communicative and political practices in different societies globally. Empirically, we analyse a conspiracy theory circulating in Nigeria between 2018 and 2019 purporting that Nigerian President Buhari had died and the man in office was his ‘clone’. Conceptually, our analysis intersects with Achille Mbembe’s work on power in the postcolony, to illustrate how it is possible to adopt alternative forms of normativity that eschew the stigmatisation and exclusion that has prevailed, but still offer evaluative frameworks to locate conspiracy theories in contemporary digital environments. We engage with Mbembe’s ideas about how humorous and grotesque forms of communication can result in the zombification of both the ‘dominant’ and those ‘apparently dominated’. We argue that zombification as a theoretical intervention provides a useful addition to the conceptual and normative repertoire of those studying conspiracy theories, between the poles of dismissal/condemnation and pure curiosity/acceptance of what is said.