From the Concept Art Division
Earlier this year I went to see Sonic 2 with my kid and I was absolutely blown away by the quality tech and robot designs in the film. The show stealer though was the Robotnik Mecha at the end of the movie. It saved the film, if you ask me.
I was delighted to see this concept art for the robot posted on Artstation by one of my favorite artists Michal Kus.
You can see more Robotnik Mecha concept art here and here.
Watch the final battle here: LINK
-Jake