▁been ▁the ▁" N ight m are ▁C af eter ia " ▁segment ▁in ▁the ▁season ▁six ▁episode ▁" Tree house ▁of ▁Hor ror ▁V ". ▁The ▁idea ▁for ▁" L isa ▁the ▁Veg et arian " ▁came ▁to ▁him ▁while ▁he ▁was ▁working ▁on ▁another ▁script ▁for ▁the ▁show . ▁C ohen ▁could ▁not ▁concent rate ▁on ▁his ▁task ▁because ▁he ▁was ▁waiting ▁for ▁l unch , ▁and ▁on ▁the ▁back ▁of ▁the ▁script ▁he ▁scri b bled , ▁" L isa ▁becomes ▁a ▁veget arian ? ". ▁C ohen ▁showed ▁the ▁note ▁to ▁writer ▁Br ent ▁For r ester , ▁who ▁liked ▁the ▁idea . ▁Show ▁runner ▁David ▁M irk in ▁then ▁approved ▁the ▁story ▁when ▁C ohen ▁pitch ed ▁it ▁to ▁him . ▁M irk in ▁had ▁just ▁become ▁a ▁veget arian ▁himself , ▁and ▁later ▁noted ▁that ▁many ▁of ▁Lisa ' s ▁experiences ▁in ▁the ▁episode ▁were ▁based ▁on ▁his ▁own . ▁ ▁W riter ▁Bill ▁Oak ley ▁suggested ▁the ▁episode ' s ▁bar bec ue ▁scenes . ▁C ohen ' s ▁first ▁draft ▁contained ▁a ▁more ▁philosoph ical ▁argument ▁between ▁Lisa ▁and ▁H omer ▁about ▁e ating ▁meat , ▁but ▁Oak ley ▁told ▁C ohen ▁that ▁the ▁story ▁needed ▁something ▁more ▁specific ▁to ▁serve ▁as ▁the ▁basis ▁of ▁H omer ▁and ▁Lisa ' s ▁dispute . ▁George ▁Meyer , ▁a ▁writer ▁known ▁among ▁the ▁staff ▁for ▁his ▁" b izar re ▁physical ▁j okes ", ▁contributed ▁the ▁idea ▁of ▁the ▁bar bec ue ▁p ig ▁getting ▁caught ▁in