A metal coffin that Ye Si Ren sleeps in while he lives in the Ass Pub (老屁股). It can vanquish the sleeper's original dark powers/instincts or suppress/prevent them from growing out again. However, as side effect, the coffin will cause the sleeper's hormones to increase, making him/her act on sexual instincts. It can also protect the sleeper from outside harm. Jiu Wu has also slept in this coffin to rid of his evil instincts.