This article addresses the complex role of mushrooms, particularly that of the fly agaric (Amanita muscaria) [Russian: Mukhomor], in the art of Moscow conceptualism in a broad setting. This paper explores the mythopoetic theme of mushroom-induced beliefs, which influenced the Moscow conceptualists, and employs background historical scholarship by R.G. Wasson, V.N. Toporov, T.J. Elizarenkova, and others. Aside from the mushrooms per se that were particularly important for Moscow conceptualism, this article also mentions various ethno-botanical entheogens (i.e. biochemical substances such as plants or drugs ingested in order to undergo certain spiritual experience, or “generating the divine within”). Apart from analyzing the ethnobotanical historical background of manifesting hallucinogenic mushrooms on the Russian soil (including Siberia), this article focuses on Pavel Peppershtein’s novel Mifogennaia Liubov’ Kast (The Mythogenic Love of the Castes), which was co-authored with Sergey Anufriev. As the narrative of the novel unfolds, its main character, the Communist Partorg (Party Organizer) Dunaev, is wounded and shell-shocked at the very beginning of the Great Patriotic War (World War II). Partorg Dunaev finds himself deep in a mysterious forest, where he inadvertently snacks on unknown hallucinogenic mushrooms. He subsequently transforms into an exceptionally strong wizard who is capable of fighting spectral enemies both on earth and in heaven. The reader discovers the so-called “parallel war” sweeping over the Russian territory where legendary Russian/Soviet fairy heroes are locked in combat with their opponents, the characters of the Western children’s tales, and books. A heroic mushroom-eater, Partorg Dunaev joins one of the sides in this fight and gradually reaches the “utmost limits of sacrifice and self-rejection.” This article contextualizes the fungi-entheogenic episodes of Moscow conceptualism into a broader sphere of constructed visionary/ hallucinogenic reality by focusing on psilocybin fungi, particularly the fly agaric/Amanita muscaria/Mukhomor, and their cultural significance.