Carol Burnett, Will Arnett, Seth Rogan, Isla Fisher, Dan Fogler, Amy Poehler, Dane Cook, Jaime Pressly and Jonah Hill are all lending their voices for the cast of the CG-animated comedy, Horton Hears a Who for 20th Century Fox Animation and Blue Sky Studios.

Jim Carrey will play Horton and Steve Carell will play the Mayor of Who-ville in the adaptation of the Dr. Seuss book; according to Variety, Burnett will voice the role of the always skeptical Kangaroo, however, no other characters were announced.

Cinco Paul and Ken Daurio wrote the screenplay; Horton Hears a Who opens in theaters March 14, 2008.

Dr. Seuss' Horton Hears a Who was released March 14th, 2008 and stars Jim Carrey, Steve Carell, Carol Burnett, Will Arnett, Seth Rogen, Dan Fogler, Isla Fisher, Jonah Hill. The film is directed by Jimmy Hayward, Steve Martino.