When an elephant named Horton hears a speck of dust cry for help, he's determined to protect the residents of the town of Whoville -- despite ridicule from his neighbors -- in this adaptation of the beloved children's story by Dr. Seuss. Steve Carell steps in as the mayor of Whoville, with an all-star cast of voice talent that includes Carol Burnett, Seth Rogen, Will Arnett, Amy Poehler and Jim Carrey as Horton.