▁the ▁sp ill way ▁and ▁flying ▁into ▁the ▁air . ▁C ohen ▁cred its ▁writer ▁John ▁Sw art zw el der ▁for ▁insp iring ▁the ▁scene ▁in ▁which ▁H omer ▁finds ▁it ▁impossible ▁to ▁believe ▁that ▁ba con , ▁ham , ▁and ▁p ork ▁ch ops ▁could ▁possibly ▁come ▁from ▁the ▁same ▁animal . ▁ ▁According ▁to ▁C ohen ▁it ▁was ▁based ▁on ▁a ▁real ▁statement ▁made ▁by ▁Sw art zw el der , ▁who ▁was ▁going ▁on ▁and ▁on ▁about ▁how ▁amaz ing ▁the ▁p ig ▁is ▁for ▁the ▁variety ▁of ▁cut s ▁of ▁meat ▁that ▁come ▁from ▁it . ▁ ▁Vo ice ▁acting ▁ ▁At ▁the ▁time ▁the ▁episode ▁was ▁being ▁written , ▁Paul ▁McC art ney ▁was ▁the ▁only ▁living ▁member ▁of ▁The ▁Beat les ▁who ▁had ▁never ▁appeared ▁on ▁The ▁Sim ps ons . ▁John ▁L enn on ▁died ▁before ▁the ▁show ▁was ▁created , ▁but ▁Ring o ▁St arr ▁and ▁George ▁Harrison ▁had ▁guest ▁star red ▁in ▁ 1 9 9 1 ▁(" Brush ▁with ▁Great ness ") ▁and ▁ 1 9 9 3 ▁(" H omer ' s ▁Bar bers h op ▁Quart et "), ▁respectively . ▁The ▁staff ▁wanted ▁to ▁bring ▁McC art ney ▁onto ▁the ▁show , ▁and ▁David ▁M irk in ▁thought ▁" L isa ▁the ▁Veg et arian " ▁would ▁be ▁an ▁attract ive ▁story , ▁since ▁McC art ney ▁is ▁a ▁veget arian ▁himself . ▁McC art ney ▁agreed ▁to ▁appear , ▁but ▁requested ▁that ▁Lisa ▁remain ▁a ▁veget arian ▁for ▁the