"The Simpsons" is losing one of its legendary voice actors. Pamela Hayden, who has voiced the character of Bart's best friend Milhouse Van Houten (as well as bully Jimbo Jones, next door neighbors Rod and Todd Flanders and many other iconic characters), is retiring. Hayden has been credited on almost 700 of the show's 774 episodes to date. In a statement, Hayden said, "The time has come for me to hang up my microphone, but how do I say goodbye to 'The Simpsons'? Not easily." See a tribute video to Hayden and her work below...