This is from Adam Hastings, an artist I was referred to recently. His website is pretty cool, with all kinds of different fandom related stuff. Stop by, if you get a chance.
I love that little imaginative touch of having his "hands" (or the ends of the tentacles) being different. The one on the left (which would be Otto's right hand) is nice and threatening. I imagine the one on the right (Otto's left) would be used for ordinary grappling and scientific work.