Introduction to Wooden Fish and Zhongchu: According to the fourth volume of "Zu Ting Shi Yuan" compiled by Shi Shanqing of the Northern Song Dynasty, "An Note on the Phenomenon of Things", there is a wild beast named Pulao on the seaside, which often forages on the shore. But it is very afraid of whales. When it sees a whale, it screams. Its cry is very similar to the sound of a bell. So, people cast the shape of Pulao on the bell and made the gong for striking the bell into the shape of a fish.