Two characters borrowed from Chinese astronomy, where they named a kind of meteor, and first written in Japan in 637 for a noise that crossed the sky. An old gloss reads them not as tengu but as amatsukitsune, heaven fox. When the word returns in the tale literature of the twelfth century it belongs to the mountains and to the harassment of Buddhism, and by the Edo period it wears the dress of the mountain ascetic and has a register of forty-eight named great tengu, each with his peak.