 " Lisa the Vegetarian " has received positive reviews from television critics and the staff of The Simpsons . Among the show 's staff , Mirkin , Kirkland , Groening and writer Ian Maxtone @-@ Graham list it as one of their favorite episodes . In the DVD audio commentary for the episode , Mirkin called the opening sequence at the petting zoo one of his favorite set pieces in the show 's history . He thought it was " absolutely hilarious " , and praised Kirkland for his animation . Mirkin also enjoyed the use of Apu in the episode , because Apu shows Lisa that " the way to get people to change is through tolerance and understanding . " Groening considers the joke in which the family forms a conga line one of the " high @-@ points " in the history of The Simpsons . 
