Why is it important to have flat characters in stories?

Question

What are some examples of flat characters that were on a tv show or movie how did there role add to that show?

Answer 1

Well an example of flat characters that contribute to movies/shows is Eore the donkey in whiney the poo.

     Ferris Bueler's day off the teacher is a way flat character and creates one of the funniest parts of the movie.

     Its Important to have flat characters sometimes for comic relief but also as a comparison to other characters which gives them more color.