Dr. Seuss' Horton Hears a Who!

In the Jungle of Nool, a caring, imaginative elephant named Horton (Jim Carrey) takes a dip in the pool. A dust speck floats past him in the air, and he hears a tiny yelp coming from it. Believing that an entire family of microscopic creatures are living on that speck, he places it on top of a clover that he holds in his trunk.

In fact, he finds out the speck harbors the city of Whoville and all its inhabitants, led by Ned the Mayor (Steve Carell). Ned has a loving wife (Amy Poehler), 96 daughters, and one son named Jojo (Jesse McCartney), who, by Who law, is next in line for the mayoral position, and as such, gives it his best effort to give Jojo enough attention. Unaware to Ned, Jojo doesn't share his father's wish.

Horton and the Mayor both agree that Whoville needs a more permanent, stable environment, and Horton resolves to place the speck atop Mt. Nool, the safest place in the jungle. This outlook earns Horton nothing but ridicule from the inhabitants of Nool, especially from the strict Sour Kangaroo (Carol Burnett), who tries to get Horton to give up the speck, so as not to put ridiculous ideas into the heads of the children. Ever faithful to his motto, "A person's a person, no matter how small," Horton refuses. Also showing disbelief toward Horton are the Wickersham brothers (all voiced by Dan Fogler), a group of bullish monkeys who love making misery.

All the small incidents that Horton experiences on his trek across the jungle have a catastrophic effect on Whoville (as an example, leaving the speck outside overnight will cause it to frost, thereby, making it snow in Whoville, during the summer). Ned has a rough time warning the city council of the unusual occurances caused by the speck being carried everywhere, as nothing in Whoville has ever gone wrong since it was founded. As the other Whos become suspicious, the Mayor finally reveals his outlandish prophecy to them, but the Whos don't believe him any more than the animals believe Horton.

Sour Kangaroo enlists a nefarious vulture named Vlad Vladikoff (Will Arnett) to get rid of the speck by force. Vlad manages to steal the speck and drop it from hundreds of feet into a valley full of identical clovers. The impact nearly demolishes Whoville like an earthquake, yet Horton finds the right clover, after painstakingly picking 2,999,999 clovers through the field. The earthquake is enough to convince the rest of the Whos that the Mayor is not crazy, and they all tell Horton they believe in him.

Sour Kangaroo finds out that Horton still has the speck, and, as her patience completely runs out, forms a mob by telling lies to get rid of the speck once and for all. They plan to rope and cage Horton, but Kangaroo turns this into a chance for attention, and offers Horton an ultimatum: give up the speck and "admit" he was wrong, or pay the price. Despite a heartfelt speech from Horton that clearly touches the animals, Kangaroo still takes this refusal as an insult, orders them to proceed with the torture, and drop the speck into a pot of boiling beezlenut oil, which is shown to have acidic properties.

The Mayor enlists all of his people to make noise, so the animals can hear them. Jojo runs off to the old , abandoned Star-Study-Tower. Inside, he reveals his ingenious invention, the Symphoniphone, a giant machine that serves as an orchestra. Still, Kangaroo doesn't hear anything and drops the clover. In a last-ditch effort, Jojo grabs a horn, runs up the highest tower and yells "YOPP!!!" A sound wave emerges and ripples up to the clouds, which are already under a lot of stress, and collides with them, causing an explosion. The Whos cries are sent rocketing through the resulting hole. Rudy then snatches the clover and holds it up. Hearing their (the Whos) cries, the animals finally realize the atrocity they almost committed. Sour Kangaroo is shocked and ashamed, but Horton forgives her, and at the end of the film, everyone, including Sour Kangaroo, helps Horton carry the speck up to the top of Mt. Nool. At the end, the camera zooms out, revealing that, along with numerous other worlds, the Jungle of Nool is... a speck.