I got an email with these little beauties today and I couldn't help but share. I think my favorite is the rogue elephant.
At the bottom, there's a little story from Kevin's graduate student instructor days. I wish he had a picture of that one.
When I was teaching an undergrad class at Michigan, one exam problem asked the student to calculate the power output of a reactor given a host of information. One student had a bunch of calculations, ultimately crossed them off, wrote "1.21 jigawatts", and drew a picture of the Delorian from Back to the Future.
I gave them some partical credit due to the high quality of the Delorian drawing which included a driver that looked somewhat like Michael J. Fox.