Jim Carrey gets top billing in the Horton Hears A Who cast, but who else lends their voice to the movie? Here’s a guide to its cast and characters.

Here’s a quick guide to the Horton Hears A Who cast and the characters they voice. It’s fair to say that Hollywood adaptations of Dr. Seuss' books have been a bit hit and miss. Movies like How The Grinch Stole Christmas or The Lorax, for example, have been big box office hits but received mixed reviews from critics. The Cat In The Hat, meanwhile, was so bad that Dr. Seuss’ widow Audrey Geisel vowed to never let Hollywood make a live-action adaptation of her late husband’s books ever again.

Luckily, Geisel didn’t take a stand against all Dr. Seuss adaptations, otherwise Horton Hears A Who wouldn’t have happened. Based on his 1954 book of the same name, the animated film stands out among other big screen Dr. Seuss adaptations because it wasn’t just a box office success but a hit with critics too. It stays faithful to its source material and tells the tale of a kind-hearted elephant (the titular Horton, voiced by Jim Carrey) who vows to protect the microscopic inhabitants of a tiny world called Whoville.

It’s easy to see why Horton Hears A Who was a hit. It’s a charmingly animated movie with a heartwarming message about looking out for the little guy and boasts a star-studded voice cast. Read on for a rundown of the Horton Hears A Who cast and their characters.

Jim Carrey – Horton

Jim Carrey tops the Horton Hears A Who cast as Horton – a kindly elephant who finds a speck of dust that is home to tiny city Whoville. Horton promises to protect Whoville and subsequently sets out to find a safe place for it to reside. This was Carrey’s second Seuss film after How The Grinch Saved Christmas.

Steve Carell – Ned McDodd

Ned McDodd is the eccentric mayor of Whoville and has 96 daughters, a son named JoJo (Jesse McCartney) and a wife named Sally (Amy Poehler). He’s voiced by Steve Carell who has worked with Jim Carrey several times during his career.

Carol Burnett – Sour Kangaroo

Comedy legend Carol Burnett lends her voice to the Horton Hears A Who cast as the Sour Kangaroo – a domineering marsupial who is the head of the jungle that Horton lives in and denies the existence of Whoville.

Will Arnett – Vlad Vladikoff

Vlad Vladikoff is a sinister vulture recruited by the Sour Kangaroo to get rid of the speck of dust Whoville resides on. He’s voiced by Arrested Development star Will Arnett who adopted a Russian accent for the role.

Seth Rogen – Morton

Seth Rogen rounds out the main Horton Hears A Who cast as Horton’s best friend Morton. He's a mouse who is skeptical about Whoville but nevertheless helps his pal on his mission to find a safe place for the tiny city.

Next: Jim Carrey vs. Benedict Cumberbatch: Who Is A Better Grinch?