Sadly, legendary comedy actress Marcia Wallace, best known for providing the voice of Edna Krabappel on The Simpsons, recently passed away of breast cancer at the age of 70. Her career in show business dates back to the 1960s and here’s one of her earliest jobs in a commercial for Crest toothpaste as a bus passenger who is willing to hold up everybody so that little Sam can brag about having only one cavity.