what movie?

I was thinking about my favorite movies this morning on the bus ride to work. Can you name the movie from the riddle below?

Three tomatoes are walking down the street -- a poppa tomato, a momma tomato, and a little baby tomato. Baby tomato starts lagging behind. Poppa tomato gets angry, goes over to the baby tomato, and squishes him... and says, 'Ketchup.'