Woodblock print of the Namazu and the god Ebisu sleeping on the kaname-ishi rock.

The Namazu, also called the Onamazu, is a creature in Japanese mythology and folktales. The Namazu is a gigantic catfish said to cause earthquakes and tremors. Living in the mud under the Japanese isles, the Namazu is guarded by the protector god Kashima, who restrains the catfish using the kaname-ishi rock. Whenever Kashima lets his guard down, Namazu thrashes about and causes violent earthquakes. The Namazu rose to new fame and popularity after the Ansei great earthquakes that happened near Edo in 1855. This led to the Namazu being worshipped as a god of world rectification (yonaoshi daimyojin), sent by the gods to correct some of the imbalances in the world. Catfish woodblock prints known as namazu-e became their own popular genre within days of the earthquake. They were usually unsigned and often depicted scenes of a namazu or many namazu atoning for their deeds. They were quickly squashed by the Tokugawa Shogunate, the prints censored and destroyed, with only a handful surviving to this day. (Photo by: Pictures From History/Universal Images Group via Getty Images)