10 Incredibly Subtle Jokes From The Simpsons You Might Have Missed

6. Mothballs ('Special Edna')

After Skinner is forced to cancel yet another date with Edna, Bart steps in to accompany her to the movies. This comes as quite a surprise to Lisa, who later teases her brother by asking ''What happened to the Bart Simpson who put mothballs in the beef stew?'' For the casual viewer, the line is no more than a reference to some (presumably offscreen) prank. And yet, for the more ardent fan, it might sound somewhat familiar. If you're struggling to place it, try to hear it in Bart's voice. ''..Homer was yellin', ' Bart!' Mom was too, Because I put mothballs in the beef stew...'' Now try to imagine that these are lyrics to a painfully Nineties rap song called 'Do The Bartman'. Because, erm, that's what they are.