Millie is a cow with a mission. Nothing in life gives her greater joy than to scare the pants off the mail carrier. Every day, she lies in wait; every day, she finds a great new spot to hide; and every day, she succeeds. But someone's got to break this cow of her bad habit. The mail carrier is developing a cow phobia, and the farmer never gets any undamaged packages. At last the mail carrier develops a foolproof plan to stop Millie for good. Too bad he forgot to make the plan cow-proof.