Flying Sheep (from Monty Python's Flying Circus)

 (A tourist approaches a shepherd.  The sounds of sheep and the
  outdoors are heard.)

 Tourist:      Good afternoon.
 Shepherd:     Eh, 'tis that.
 Tourist:      You here on holiday?
 Shepherd:     Nope, I live 'ere.
 Tourist:      Oh, good for you.  Uh...those ARE sheep aren't they?
 Shepherd:     Yeh.
 Tourist:      Hmm, thought they were.  Only, what are they doing up
               in the trees?
 Shepherd:     A fair question, and one that in recent weeks 'as been
               much on my mind.  It's my considered opinion that
               they're nestin'.
 Tourist:      Nesting?
 Shepherd:     Aye.
 Tourist:      Like birds?
 Shepherd:     Exactly.  It's my belief that these sheep are laborin'
               under the misapprehension that they're birds.  Observe
               their be'avior. Take for a start the sheeps' tendency
               to 'op about the field on their 'ind legs.  Now witness
               their attempts to fly from tree to tree.  Notice that
               they do not so much fly as plummet.

 (sound effects: "Baaa baaa ... flap flap flap ... whoosh ... thud.")

 Tourist:      Yes, but why do they think they're birds?
 Shepherd:     Another fair question.  One thing is for sure, the
               sheep is not a creature of the air.  They have enormous
               difficulty in the comparatively simple act of perchin'...

 (sound effects: "Baaa baaa ... whoosh ... thud" and the Tourist winces)

               ...As you see.  Talk about the blind leading the blind.
               Trouble is, sheep are very dim.  Once they get an idea
               in their 'eads, there's no shiftin' it.
 Tourist:      But where did they get the idea?
 Shepherd:     From Harold.  He's that most dangerous of creatures, a
               clever sheep.  'e's realized that a sheep's life
               consists of standin' around for a few months and then
               bein' eaten.  And that's a depressing prospect for an
               ambitious sheep.
 Tourist:      Well why don't just get rid of Harold?
 Shepherd:     Because of the enormous commercial possibilities, should  'e
               succeed.