Very interesting! And I love your color choices., and your mix of organic structures with metal/technological build.
Critique wise, I want to say that there's something about the water streaming off the drone that bothers me. I'm assuming the drone is just coming to surface after being under water. Water WOULD stream off if so, but not in such an unbroken stream/curtain as that. Break up your water a bit, like how it's coming off this whale's tail: [link] Right now it looks like your drone is actually a fountain, with some kind of water source on top. Unless he's supposed to be massive, but your ripple sizes indicate a much smaller bot (smaller than a human).
I spend way too much time drawing water, in case you're wondering.