And here's the finished product. You'll notice I added some "color" and texture to their clothes, gave the 'limbo-er' some teeth, and added hair details on several of the characters.
I also whited out and re-drew a couple of things that didn't sit well with me: the 'limbo-er's' right hand and the right arm of the girl behind the Centaur. I also lowered the Centaur's rump and rounded his shirt tail.
You may have noticed the centaur's expression changed from anxious to angry. I feel making him less sympathetic sharpens the humor a tad.
Lastly, I added the caption to drive home "Theo's" feelings. Why don't I consider that redundant? Because it's not Theo's own thoughts telling us what his face already does, it's the voice of the serious commentator adding a bit of gravity to the absurd situation.
That's it. As you may have gathered by now, it doesn't take an art genius to produce a cartoon. It does require good ideas, the willingness to put the pencil and pen to the paper, and in my case, an eraser, too.