Chinese Innkeeper Worm

Urechis unicinctus, known as the fat innkeeper worm or penis fish, is a species of marine spoon worm in East Asia. It is found in Bohai Gulf of China and off the Korean and Hokkaido coasts. It is not to be confused with a closely related species, Urechis caupo, which occurs on the western coast of North America and shares common names. The body is about 10–30 centimetres (4–12 inches) long, cylindrical in shape and yellowish-brown in color. On the surface of the body, there are many small papillae.