Foster's Home for Imaginary Friends

Bloo tricks Mac into making crank calls to Mr. Herriman. Their joke is simply blowing raspberries into the phone, redialing again and again. Each time Herriman tries to get back at them by doing the same thing, it isn't them redialing, it's Frankie asking about groceries in the mall. The last call Herriman gets wasn't from Mac and Bloo or Frankie. It was from Madame Foster.