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.