this is a really nice looking drawing, it could be done right now. 2 things you might consider is that a) just try it out with some color and b) he (or she) looks really static. maybe some bubbles could solve this, but i think it might just be the gesture that could be tweaked a little to make him look a little more floaty-jelly-octopussy-ish rather than stiff. but those are all fine points, i think it also looks good as is.
yeah good color. I feel this idea needs to be reworked to give the octopus either more extravagant weapons( I picture it hefting some kind of heavy machine gun ) or remove all of the weapons except the knife. But that would mean redoing it and it looks like you are capable of that. If not I'd would say just sub this.