One of the first few designs I did starting out as a concept artist for Exodus games, which was redraw awhile later. (Thumbnail is final design.)
Final Concept
Isolated Side view + intended visual size compared to humanoid.
Misc. Reference for 3D modeller
Older Concept art prior to re-do of design. This is one of the first units I ever designed while the project entered fulltime development, so it took awhile to adjust to intended visual vibes.
Previous stage from the actual finished design. I believe it was just over a years time between these two design phases. I did a lot of studying in my freetime.