Tesso

◆ The legend

A giant rat with teeth as hard as iron. It is said to have begun as the grudge of a single monk, and to have swept into a temple at the head of countless rats, gnawing apart its precious sutras and Buddhist statues. To a temple, the sutras were the greatest treasure of all, so a rat that chewed through them may have been about the worst enemy a monk could imagine.

The tale behind it is that of Raigo, a monk of Mii-dera in Omi Province, today's Shiga Prefecture. Asked by the emperor to pray for the birth of a prince, he succeeded, yet the reward he had been promised never came. Raigo died still consumed by resentment, and his rage, so the story goes, became a rat that set out for Enryaku-ji on Mount Hiei, the temple that had blocked his reward. That is why it is also called "Raigo's rat," and in the Edo period the painter Toriyama Sekien drew it under the name "tesso," the iron rat.