In the west lives a lamb whose pride and joy is his wool. When a man comes and shears him, the lamb becomes depressed. It takes a Jackalope to teach him to bounce back from life's troubles.
This is the first theatrical short to have dialogue. To date, this and Lava are the only Pixar shorts to feature dialogue that aren't based on a pre-existing property. Indeed, the man talking on the radio in Day & Night is a recording of a speech by Dr. Wayne Dyer.