We love pigs. Sassy little Olivia is a longtime favorite in our household.
Leighton and Mairin quickly elevated Mercy to Olivia status and we subsequently bought the four Mercy Watson books we did not have.
Mercy is a pig, the pet (nay, child) of the Watsons of Deckawoo Drive - born of the imaginations of author Kate DiCamillo (The Tale of Despereaux and Because of Winn-Dixie) and illustrator Chris Van Dusen.
Although Mr. and Mrs. Watson believe that Mercy is sophisticated enough to drive a car, trick or treat or fight crime, Mercy's single motivation is food, specifically "warm toast with a great deal of butter on it."
Mercy Watson books are entertaining for all ages and wonderful for early readers. You can buy them individually, or as a set.
My only warning is that merely opening the book generally brings about a request for a snack of "hot buttered toast". I recommend having bread and butter on hand at all times.