Why does everyone like to talk about the mule?

The people of Eatonville love to pass the time telling stories on the porch. One of their favorite topics is Matt Bonner's yellow mule. Lige Moss, Sam Watson, and Walter love to tease Matt for never feeding the mule and for working the mule too hard. The mule becomes famous as the town's first freed animal, and it wanders about the town getting fat until it dies. There is a funeral for the mule at the swamp outside of town.