This image was uploaded to the Sankaku Complex image board about four years ago, but no artist information is available. It has subsequently appeared on other image boards (here and here) and is advertised as being part of the content of a commercial porn site called Hentai Tentacles. However the diversity of promotional material there makes me suspect that the site’s claim to offer “100% exclusive Hentai” is false; it looks more like images collected randomly from around the ‘net. However if the claim were actually true and the art was truly created for exclusive display on that paysite, one might expect that artist information would only be available to members inside the pay area of the site, or perhaps not at all.
Image provenance by Bacchus at Erosblog.