This artwork is entitled Rapture – For Alex and it’s a collaboration between digital artist Jana Schirmer (janaschi) and Johannes Voß (algenpfleger). Schirmer, who is a digital artist from Leipzig, explains:

“Alex’s birthday was on Oct 1st. Deciding on a subject matter was easy and hard at the same time. We pretty much knew what Alex likes, but he didn’t want any more Dickbutt, so we had to use Raupe-kun instead!”

There’s a breathless post criticizing the artwork for being pornographic here; it suggests that Raupe-kun means something like “caterpillar fetish”.
Image provenance by Bacchus at Erosblog.