The Simpsons: 30 Greatest Ever Opening Credits Gags

29. Professor Frink's Sex/Kill-Bots

The billboard gags came on the scene in 2009 from series 20 onwards. They tend to be slightly more bleak and/or seedy than the other visual jokes and professor Frink's versatile invention is a perfect example of this. First aired: September 26 2010 Episode: Elementary School Musical