Habitat: Buddhist temples
Appearance: Teratsutsuki is the onryō of a man who lived in the 6th century CE, Mononobe no Moriya. It was sighted at Hōryū-ji and Shitennō-ji temples, where it took the form of ghostly woodpecker and tried to destroy the temples until it was driven away by Prince Shōtoku.
Legends: Long long ago, when Japan was still called Yamato and the capital was located in what is today Nara, the nobility was divided into two different types: shinbetsu, clans that claimed to be descended from the gods, and kōbetsu, clans that claimed to be descended from the imperial family. The highest ranking titles in these groups were Muraji, for the shinbetsu clans, and Omi, for the kōbetsu clans. In the 6th century CE, when Buddhism was brought to Yamato from China, it caused a great deal of rivalry between the shinbetsu and kōbetsu nobility.
Mononobe no Moriya was the leader of the Mononobe clan and a Muraji. The Mononobes, a shinbetsu clan, strongly supported the old Shinto religion. His rival, Soga no Umako, was an Omi, and supported the promotion of Buddhism throughout Yamato. Mononobe no Moriya and Soga no Umako held considerable power in the imperial court. During the reign of Emperor Bidatsu (572-585), Mononobe no Moriya held higher favor with the emperor, but when Emperor Yōmei took power in 585, Moriya’s favor fell and Soga no Umako’s rose, as the new emperor was a Buddhist.
Emperor Yōmei died in 587, after which the Mononobe clan and Soga clan tried their best to influence the succession of the imperial title. Each of them supported a different prince to become emperor, and they fought bitterly for their clans’ interests. Finally, war broke out between the two rival clans. Mononobe no Moriya set fire to Buddhist temples and tossed the first statues of the Buddha brought to Yamato into the canals in his fight to purge the foreign religion from his homeland. Moriya and Umako mustered their armies and met on the battlefield in Kawachi. There, at the Battle of Mount Shigi, Mononobe no Moriya was killed by Soga no Umako and Prince Shōtoku, and the Mononobe clan was almost completely exterminated. Afterwards, the Soga clan rose to even higher prominence, and Prince Shōtoku, a devout Buddhist, began the construction many new Buddhist temples.
The spirit of defeated Mononobe no Moriya did not rest, though. As he lay dying in hatred and resent, Moriya transformed into an onryō. His ghost took the form of a ghostly woodpecker, which would later be seen at the temples built by Prince Shōtoku. The bird pecked furiously at the wooden buildings, determined even in death to destroy the heretical new religion. Prince Shōtoku was finally able to drive away this teratsutsuki by magically transforming into a hawk and attacking it. After that, the ghost of Mononobe no Moriya was never seen again.