I wanted to redesign a Pokémon as if it was from a less-kid-friendly universe. My favorites are Tentacruel and Espeon. Espeon is a zen purple cat-thing and Tentacruel is a pissed off, malevolent jellyfish, so the choice seemed clear of which one to do.
This involved adding a bit more realism to the design and trying to justify some of the reasons why the original looks the way it does. I wanted to stray as far as I could from the original while remaining recognizable to those familiar with it. I am pretty happy with how that balance worked out in the end and I've learned a lot of ways to improve this workflow the next time I try something like this. About halfway in I started to notice it looks a bit like Samus' old gunship; oh well!
You may have to click the image to adjust the zoom since it might be initially shrunken.
If you are not familiar with Pokémon you can click here to see the official art of Tentacruel. Alternatively, you can click here to see a haunted toaster.
I looked up some reference on the Atlantic blue crab to see how nature works with blue, so that I could stick with the original's coloring but add in some other hues to better the believability.
Love how you even made the coloration look convincingly naturalistic while still sticking to the original pallet.