It is a Season 5 episode called 'The Dwarf in the Dirt' and it was in there because The Simpsons (also a FOX program) were celebrating their something th (I am not sure what number sorry) episode and so they had little cameo Simpson things in every FOX TV program that night. Hence why they had the Homer Simpson x-ray in the background. For future reference this type of thing would better fit the 'Answers' part of the group. :)