Putting this image through saucenao returns this pixiv link by this artist, neither of which seem to exist anymore. Google searching (pixiv user "1574957") returns this which claims that this image is by the same artist as the image above. The artist's name according to all sources I can find is うんこりん, which should romanize as "un korin" based on wikipedia, google translate, and nihongo, which is why I'm using that as the artist tag.
