This concept is my version of what Cthulhu would look like. I liked the idea that Cthulhu is a massive larger than life creature, so enormous that it cannot be understood as a living being, but almost as a landscape.
For a 1km tall being, a neck is a very fragile structure that would easily collapse, specially considering the amount of tentacles that hang from his head. I considered the body as a big fat mass of flesh, and a little head reinforces the size of the rest of the body.
I thought that Cthulhu should have wings similar to the fins that squids and cuttlefishes have, but I couldn’t find the way to make it work. Still, this wings would not let him fly, but at least they give him a more menacing look.
I depicted Cthulhu’s forearms as an amalgamation of claws and octopus beaks that he would use to catch and destroy. In the center of what we could call “palm”, a mouth-like hole opens, from where sensitive tentacles can emerge to manipulate objects.
Hope you like it!