Horton Hears a Who!

""A person's a person, no matter how small.""

Horton Hears a Who! is a 1954 children's book by Dr. Seuss, adapted into a 1970 animated special by MGM Animation/Visual Arts (the studio responsible for the classic animated adaptation of How the Grinch Stole Christmas) and a 2008 animated film from Blue Sky Studios (the creators of Ice Age). The book's plot also makes up a sizable part of the plot of the stage musical Seussical. It was dedicated to a Japanese friend, Mitsugi Nakamura.

Rare for Seuss, this book is a sequel (to Horton Hatches The Egg).

"Horton: I love the smell of bananas in the morning!"
 * Adaptation Expansion: The movie.
 * Art Shift: Happens twice in the movie. The first time is a 2D animated sequence drawn completely in Seuss' distinctive style. The other is an Animesque action sequence/daydream.
 * Ascended Extra: Jojo in both the movie and Seussical.
 * Awesome McCoolname: Vlad Vladikoff. You know it's true.
 * Bits of Me Keep Passing Out: In the movie, the Mayor is at the dentist when an earthquake (caused by the speck the Whos all inhabit moving) occurs, and the Novocaine needle ends up in his arm, which remains limp and useless for some time afterward.
 * Brick Joke: in the movie.
 * And Burt from accounting makes an appearance.
 * On the rope bridge, Horton thinks that inhaling deeply will make him lighter. Near the end Katie inhales deeply... and floats away.
 * The Cameo: In the 1970s TV version he makes a cameo in the Who chorus near the end.
 * And the modern version: Watch the new version of the "We Are Here" chorus - if that's not the Grinch playing that tiny set of pan pipes, he's one heck of a doppelganger.
 * He also makes a cameo in Seussical.
 * Cassandra Truth: Horton's practically the Trope Codifier for people who read this book as a child.
 * Cloudcuckoolander: Katie, in the movie.
 * Also in the movie, Horton himself.
 * Subverted in the book and in Seussical because everyone in the Jungle of Nool thinks that Horton is a tad off his rocker for hearing a Who.
 * Just the sheer fact that Horton is voiced by Jim Carrey in the film qualifies him for this.
 * Continuity Nod: Horton's catchphrase in the movie was, of course, imported from Horton Hatches the Egg.
 * Creepy Child: Katie in the movie. "Aaah..."
 * Crowd Song: The end of the movie.
 * Defeat Means Friendship
 * Determinator: Horton. Sour kangaroos, weak bridges, open valleys, villainous vultures, flat cliffs, snowy mountain tops, losing the speck amongst miles of similar-looking clovers, and mobs of animals trying to rope and cage him, will. Not. Make. Him. Stop. Physically or emotionally - despite people telling him to stop believing in the Whos, Horton doesn't stop.
 * An elephant's faithful, one hundred percent.
 * Disproportionate Retribution: Sour Kangaroo is the queen of this.
 * Dying Like Animals: In the film, Whoville is filled with bats.
 * Easily Forgiven: All the "villains".
 * Emo Teen: Jojo.
 * Genre Savvy: In the film, while Horton is escaping Vlad the vulture, he briefly loses him and predicts that said vulture will pop out of nowhere eventually.
 * Getting Crap Past the Radar: In the film. "Ninety-six daughters and one son." "Busy man..."
 * Groin Attack: In the film, the mayor gets wedged between a door as several large objects strike him in the crotch.
 * Happily Ever After
 * Here We Go Again: The ending to the animated special.
 * Honorable Elephant: Horton, obviously, for the second time.
 * Hypocritical Humor: "How could he call me a boob? I would never call anyone a boob. HE'S the boob!"
 * Ignored Expert: The Mayor of Whoville in The Movie.
 * I Love the Smell of X In the Morning: In the 2008 film version:

""Don't panic... Whoever built this bridge obviously took into account that elephants will be crossing it.""
 * Karma Houdini: Sour Kangaroo, especially in the movie.
 * Of course. Horton's cool like that.
 * Large Ham: Subdued, compared to his other performances, but Jim Carey as Horton.
 * Medium Shift Gag: The previously All CGI Cartoon briefly shifts into a more traditional Animesque style as Horton imagines himself as a ninja sworn to protect the tiny world on the clover.
 * Mind Screw: What the hell are you, Katie!?
 * Word of God says she's a baby yak.
 * That was obviously not the problem.
 * Misplaced Wildlife
 * Narrator
 * Nerds Are Sexy/Hot Scientist: Dr Larue.
 * Obliviously Evil: None of the other animals intend to create the genocide their actions would result in; they simply think Horton has lost his mind.
 * One Steve Limit: The Two Vlads.
 * Only Sane Man: In the movie, Rudy [the joey] and possibly Jojo as well.
 * Recursive Reality: Horton discovers a whole world in a tiny dust speck. The TV special of it has an ending in which the main Who finds another dust speck with its own world. At one point in The Movie, Horton wonders whether the universe he inhabits could itself exist as a speck of dust to another universe.
 * Ridiculously Cute Critter: Again, Katie.
 * Rope Bridge: In the 2008 film, Horton has to cross one on his way to Mt. Nool.

"Kangaroo: If the children hear stories about worlds beyond the jungle, they'll start to question authority! Which leads to defiance, which lead to ANARCHY!"
 * Shaming the Mob: Subverted, along with the Rousing Speech, in the movie.
 * Silent Snarker: Jojo,
 * Skyward Scream: In all versions of the story,
 * Stock Footage: The 1970 special uses this quite a bit.
 * Sudden Musical Ending: And how. "I Can't Fight This Feeling Anymore" out of nowhere.
 * Suspiciously Specific Denial: The Mayor constantly reassures the Doctor that he absolutely did not have a conversation with an elephant in the sky.
 * Think of the Children: In the 2008 movie, the kangaroo rallies all the other animals in the jungle against Horton with this cry.
 * Toothy Bird: Vlad Vladikoff, a toothy vulture.
 * Totally Radical: When the Mayor tries to relate to Jojo at the beginning of the film. It fails.
 * Traveling Pipe Bulge: This happens when Horton's voice first travels down the pipe to the mayor's office.
 * Tree Buchet: How Horton gets rid of Vlad in the movie.
 * Villain Song: The Wickersham Brothers get perhaps the catchiest number in the 1970 special. They also do some chanting when caging Horton and trying to boil the clover.
 * What Measure Is a Non-Cute?: Subverted; the main villain is a kangaroo.
 * Well-Intentioned Extremist: Kangaroo is actually a subversion. It's pretty obvious that she's enforcing her rules for the sake of her own ego instead of actually protecting anybody (She goes on about protecting the children, then kicks Katie clear across the jungle.)
 * Witch Hunt: The Wickersham brothers in the 1970s version treat Horton like a Red Scare. "You're trying to stir up discontent, and take the reins of government..."
 * There's a bit of this in the 2008 movie as well.