I somewhat disagree with both ecks request for more midtones and ferons for more contrast, though I'm no expert on colors.
Imo what you need to do is utilize the colors on the first draft better. You've got the two darkest tones cramped up in the mouth, why not use 'em more? They could add alot of depth to the body. Also, I'd imagine a tentacly bad boy like this one would be kinda slimy, right now it looks more metallic. A last thing that could spice this one up a lot is
texture. Go mess it up a bit, make it more organic!
I've tried to address some of the issues I'm talking about in this quick edit:
Hope you can find use for it
Looking forward to seeing this develop
/vedsten