The Bigger the Catfish, The Bigger the Quake...

Namazu-e... Catfish prints

...but of course, you knew that.  Namazu (catfish) anciently symbolized disorder, then gradually a specific kind of disorder-- earthquakes.  The rumbling and shaking of an earthquake was said to be caused by thrashing catfish deep below in the mud (well-- it makes a certain amount of theoretical sense... sort of... vaguely... in a folklore-ish kind of way).

Great Ansei Edo Earthquake, 1855

Following the third of three great earthquakes known collectively as the "Ansei Daijishin" of 1854-55 (Great Ansei Earthquakes-- Ansei was the name of the era, as "Heisei" is now), woodblock prints of the quake destruction were produced.  But far more popular were the "Namazu-e", catfish prints, which became a way of venting at the gods (Kashima, who fell down on the job of restraining the catfish),the politicians, and the wealthy (the Namazu qua earthquake became a symbol of  the redistribution of wealth-- "Yonaoshi", or 'World Rectification').

Pink Tentacle has a great article with *lots* of prints... go have a look!  He's found zillions of beautiful Namazu-e (nice and clear, too).