Duck buying pork chop joke

A duck walked into a bakery one day and asked for a pork chop.
The baker said, "We aren't a butcher; we don't sell meat here."
So the duck left.
The following day the duck went back and asked again.
This time the Baker said, "No, if you come here again I will nail your feet
to the floor."
The following day the duck returned and asked, "Have you any nails?"
The baker replied, "No." And the duck said, "Well, I'll have two pork chops then."