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. In fact, Seuss intended for the story to be a metaphor for the American occupation of Japan after World War II.Rare for Seuss, this book is a sequel (to Horton hatches the Egg).
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.
The Sour Kangaroo is equally determined to stop Horton, to the point of siccing an angry mob on him.
Word Of God says that in the movie she was originally going to get much better comeuppence in the form of all the other animals turning their back on her but the writers decided to cut that out saying that "Dr. Seuss wasn't big on revenge".
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.
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..."
The 2008 adaptation contain examples of:
Adaptational Villainy: In the original story, Kangaroo was a Well-Intentioned Extremist who was grumpy, but not really much of a villain. Here, she's a straight-up sadist who cares more about her own ego than the other jungle animals, and seems to have a lot more fun in torturing Horton than she should. Not to mention being portrayed as borderline abusive toward the children that she claims to be protecting.
Look at the way the animals are cowering in fear of her at the beginning. Did she previously abuse them in the past?
And possibly genocidal (toward the Who's) as well. Notice how she tried to take the clover away from Horton even after she heard the Who's "we are here".
Vlad Vladikoff as well. In the original story, he didn't have much of a role. He simply just carried the clover off and dropped it. In the film, on the other hand, he's upgraded to a genuinely terrifying, dangerous, and feared character, with sharp teeth and a sadistic sense of humor. Just look at his gleeful grin when he tells Kangaroo to offer her son to him as food.
Art Shift: Happens twice. The first time is a 2D animated sequence drawn completely in Seuss' distinctive style. The other is an Anime parody action sequence/daydream, complete with mouth movements that don't match up to the voices.
Bits of Me Keep Passing Out: 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.
Groin Attack: The mayor gets wedged between a door as a large fishbowl strikes him in the crotch.
Which is to say nothing of what happens later during the Vlad chase. The Mayor rolls out onto his balcony, hits one of the railing pillars between his legs, then is shoved in further by his desk, a couch and a refrigerator. Safe to say there probably won't be a 98th daughter.