I did this drawing in college. The assignment was to design a skeletal system for a cartoon character. I got so excited about the assignment, I did two. (I'll try to post the other one another time)
I'm quite proud of this drawing. It still looks pretty good to me. I think if I were to do the same assignment today, I would tackle it with some other medium besides pastel. But the pastel gave a softer look to the cartoon figure of Popeye and helped the illusion of depth. I tried to shade the figure so that he would seem 3D. I'm not sure I'd make the wall behind the blackboard brick but, at the time, it seemed the most strikingly visual thing to do.
Forgive the reflection of the photographer. This drawing has been encased behind plastic since the early 80's and I'm not about to take it out. That's why it's lasted this long without damage.