Someone here just had a great thread asking if an octopus is useless. You might want to check that out.
On a rabbit trail though, diving in shallow water for scallops (freediving, but I had gear with me to check out a deeper fishing site for my dad...25 feet max, most of the day was freediving) upon entering the boat I find a very tiny octopus sitting on the stern....very small boat, not high above the water, so it probably washed into the side of the boat and crawled just a little to get into the boat. I put it on my face to get a picture taken. I think the thing tried to eat me. Whatever it was, it hurt!!!