This is a detailed watercolor drawing of a sea slug. The slug is a reddish-brown color and has a bumpy, textured surface. It has a somewhat elongated, flattened body with several raised, rounded protrusions along its back. Two long, slender tentacles extend from the front of the slug. The slug is depicted against a pale yellow background. There is some Japanese text written in the bottom left corner and along the right side of the image. The drawing appears to be a scientific illustration, possibly from a field study or research project.