- “It's Mr. McGreg, with a leg for an arm and an arm for a leg!”
- ―Dr. Nick Riviera
He is one of Dr. Nick's patients. After Dr. Nick finishes doing the triple bypass surgery on Homer and telling the rest of the Simpsons that it went successful, he leaves, and is stopped by Mr. McGreg, who is angry and furious for having his right leg be a right arm, and his right arm be a right leg.
Dr. Nick, in typical "Nick Riviera-fashion", simply ignores Mr. McGreg's anger after Mr. McGreg asks if he remembers him, and happily says, "Well, if it isn't my old friend, Mr. McGreg! With a leg for an arm, and an arm for a leg!"