The raiju is a Japanese cryptozoological species that occasionally fall to earth during thunderstorms. It has been described as resembling a squirrel, cat, weasel, or seahorse, but this particular illustration is of a crab-like creature which fell from the sky in 1796 in Higo-kuni, Japan.
Here is the blog article which is the source of both the information and the original image. The original image is flipped vertically only because the image of my clay copy looks bad when flipped, so if you want to read the Japanese, you'll have to rotate it 180ยบ again.
