STEVE CARELL takes on the world of DR. SEUSS in his new animated movie, 'Horton Hears a Who!,' and ET's KEVIN FRAZIER is with the new "Mayor of Who-ville"!

"This is a role I could not turn down," Steve gamely says in Seussian prose. "It would make my smile come up from a frown; it was a happy role, something I wanted to do; something I think you should see, and so should you."

In the animated film, out March 14, JIM CARREY (who also took on the title character of the live-action 'Dr. Seuss' How the Grinch Stole Christmas') plays Horton, an elephant who hears voices coming from a speck of dust. He soon discovers, to his amazement, that the land of Who-ville is located on the infinitesimal world and it's up to him to protect the people who live there. After all, a person is a person, no matter how small!

Steve plays the Mayor of Who-ville in the film, while DANE COOK, SETH ROGEN, CAROL BURNETT, JAIME PRESSLY, ISLA FISHER, JONAH HILL ('Superbad'), WILL ARNETT ("Arrested Development") and AMY POEHLER ("Saturday Night Live") also lend their voices to the animated tale.

"In Who-ville, people's clothes are essentially their own fur, and that vaguely mirrors my [chest hair]," jokes Steve, who says he's always been a fan of Dr. Seuss. "For the premiere, I'm just going to go nude -- but you won't be able to tell because I'll have dyed my chest hair blue and it will cover my entire body. It's something that I think will set me apart. My kids are going to be there too, so they'll be so excited that dad made that choice."