In one of my college investment class finals I drew a stick figure of my teacher for my final essay and received full credit. The dude said it was too funny not to reward with points... and i already had an a+ in the class... wasn't gonna affect the outcome of my grade.
I enjoyed that so much I sent it out to all the guys I graduated with. It looks like something one of them would have done almost 30 years ago. Of course that was an all boys military school where you could get away with more stuff than in a coed school.