Taylor Swift has joined the ensemble voicecast of "Dr. Seuss' The Lorax," Universal Pictures and Illumination Entertainment's CGI-animated adaptation of the children's book classic. Swift joins Danny Devito, Ed Helms, Zac Efron, Rob Riggle and Betty White in the tale of a boy who searches for a way to win the affection of the girl of his dreams. He comes across the story of the Lorax, the grumpy yet charming creature who fights to protect his world. Swift will play the dream girl of the idealistic young boy (Efron). DeVito is voice of the Lorax while Helms voices Once-ler, who in the book is never shown except for his hands and arms. Riggle plays a greedy entrepreneur while White will voice Efron's wise grandmother. The film reunites many of the players behind Illumination's first movie, "Despicable Me:" Chris Renaud is directing from a screenplay by Cinco Paul & Ken Daurio. Illumination founder Chris Meledandri and fellow "Despicable Me" producer Janet Healey are producing while Audrey Geisel, Suess' widow, serves as the film's executive producer. The film will be Swift's second entry into the movie world, after her live action debut in last year's "Valentine's Day."