A Big Piece of Garbage - S1-E8
Corrected entry: When Fry, Lela and Bender are on the big ball of garbage, Bender picks up a Bart Simpson doll, pulls the cord on its back and the doll then says "Eat my shorts". The batteries should have gone flat by the year 3000.
Correction: Dolls that have a pull cord like that don't use batteries.
Greenman37