Inspired by a nightmare  bentproplrprod had, Sandpaper is a sort of ghost that goes about slowly shredding living beings of flesh (Sandpaper is completely unable to permanently damage things not made of flesh, though an encounter in any case is unpleasant). Part of a conversation I had with  bentproplrprod ended up giving me the idea that Sandpaper is partly computerized (which you can see in his eye). In this case I figure Sandpaper is System 360. Aorta will be upgrading him soonish.