Apperantly there was a japanese urban legend of a tale that was found in the 17th century called 'Cow Head' the short was reportedly so horrifiying that readers of it had seizures and trembled for days,some even dying from the words it contained.
All traces of the story was burned and rumour tells that the only remains of the story are split into fragments,lest someone gathers the story together and unleashes its terror once more.