To examine the means whereby dragons produce fire and steam, we have studied a related species, the desert-lizard Lacerta pyrophorus. Morphological studies showed that there were in the snout three distinctive features: (1) a dorsal swelling in the pharynx, the Organ of Feuerwerk, consisting of brown adipose tissue with an extensive sympathetic innervation; (2) greatly enlarged lachrymonasal ducts, the Ducts of Kwentsch; and (3) asbestos deposits in the nasal skin, the Bestos Bodies. Physiological studies show that the Organ of Feuerwerk can, when the animal is excited, produce extremely high temperatures. We discuss how these mechanisms can produce steam and fire, and how the snout is protected. We also discuss and offer a solution to the problem of how, since dragons are invariably male, the species can be propagated.