lets take a look at lost doodles!
To the above is an image featuring the classic "fish in a suit" concept that came to me only this time it's the octopus, but whats note worthy about this page is that below it are some interesting variation on my ideas on combining "Robot" and "Fish", such as a literal robotic fish kind of hybrid and a smaller fish that is attached to various amounts of machinery. The idea behind that one is that the fish would pilot a gigantic robot all through the power of it's mind, the robot fish was just an amalgamation of the two words in a literal sense.
(Click To Enlarge)
Above is another rough of a "shark man type" nothing more really than just a development piece but back when I drew this is didn't quite know the character I was developing as well as I do know but the very basic ideas that I'm currently working on are present here but as you've seen through later designs I've dropped the aqualung but it seems like a very good idea that I want to try encorporate into the finalised versions. Finally below are two side profiles of the slightly more developed ideas I was working on at the time, I quite like the addition of goggles to the shark as I felt it brought a bit of charm to the character. It was around the point of drawing this that I settled on focusing on only the shark.