High Quality Content by WIKIPEDIA articles! "Lisa the Vegetarian" is the fifth episode of The Simpsons` seventh season. It originally aired on the Fox network in the United States on October 15, 1995. In the episode, Lisa decides to stop eating meat after bonding with a lamb at a petting zoo. Her schoolmates and family members ridicule her for her beliefs, but with the help of Apu, Paul McCartney, and Linda McCartney, she commits to vegetarianism.