Suppon on Oryo — The Legend of the Vengeful Ghost Turles
A folktale from Edo Period Japan,
A man named Kiroku had a successful suppon shop in Nigata city. Every day he butchered and served up hundreds of turtles. One day at work, his body suddenly felt heavy. At the same time, everything became cold and dark, and it felt like he was being submerged under water. He tried to shout, but no voice came out. He felt around with his hands, and felt something even colder. It was a turtle shell. All around him were hundreds of turtles, crawling over his body and dragging him down.
Finally, Kiroku managed to let out a cry of horror, which brought his wife running into the room. When she opened the door, all of the turtles vanished.
This happened night after night, until finally Kiroku had enough. He had learned his lesson, and swore an oath against the taking of life. The wrathful turtle ghosts never came again.
Translation from http://hyakumonogatari.com/