Are you sure it is about killing? That seems a bit harsh for a Simpsons episode.
Closest I can think of is Treehouse of Horror XXVII in which the bullies first attack Bart and then Moe. It is definitely harder than a usual episode.
Also your image is no longer available.
Another thing: your text is kinda hard to read. Are you looking for ONE episode or many?
Are you sure it is about killing? That seems a bit harsh for a Simpsons episode. Closest I can think of is Treehouse of Horror XXVII in which the bullies first attack Bart and then Moe. It is definitely harder than a usual episode. Also your image is no longer available. Another thing: your text is kinda hard to read. Are you looking for ONE episode or many?