The fly-agaric, with its characteristic red hat sprinkled with white spots, is the best known mushroom of Eurasian iconography, depicted countless times in children’s fairy tales and Christmas themes. Endowed with intoxicating properties and used for millennia in Siberia as a visionary shamanic source, for several centuries Western culture has also attributed deadly properties to it. The cultural genesis of this “mortalization” process brought to the opposing values of “poisonous / intoxicating” and “negative / positive”; a semantic ambivalence that has also been present in Russian culture since pre-Soviet times. The mukhomor — the Russian name for fly-agaric— was employed in the final years of Soviet power as a symbol of redemption by dissident underground movements, and its significant presence in contemporary Russian intellectual, literary and artistic production is presented on the basis of historical and ethnomycological considerations.