A list of characters featured in ''Literature/HortonHearsAWho''. Their tropes apply to different continuities, including the original 1954 book, [[WesternAnimation/HortonHearsAWho1970 the 1970 animated special]], [[WesternAnimation/HortonHearsAWho2008 the 2008 animated movie]], and even ''Series/TheWubbulousWorldOfDrSeuss''.

[[foldercontrol]]

!Jungle of Nool

[[folder:Horton the Elephant]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/movie_horton_hears_a_who_wallpaper_4.jpg]]
-->'''Voiced by:''' Kent Rogers (1st, Horton Hatches the Egg cartoon), Hans Conried (1970 TV Special), John Kennedy (''The Wubbulous World of Dr Seuss''), Creator/JimCarrey (2008 animated film)

An outgoing, big-hearted, loving, sweet, and thoughtful elephant. Horton has no tusks, lives by himself and possesses acute hearing abilities.
----
* {{Acrofatic}}: For an elephant, he is quite graceful, capable of doing a perfect swan dive into the river and climbing up a steep cliff.
* AdaptationalPersonalityChange: To some degree in the 2008 movie, while he's still a GentleGiant, he takes on a much more a hyperactive and quip heavy personality, likely due to Jim Carrey voicing him.
* AmazingTechnicolorWildlife: He's uncoloured in the books. He's usually given a grey skin tone in most adaptations, though the ''Horton Hatches the Egg'' Merrie Melodies short makes him bright pink.
* AllLovingHero: All there with his frequent mantra: "A person's a person. No matter how small".
* BewareTheNiceOnes: As can be seen when he finally gets good and pissed off during the final stretch of chasing Vlad for the clover. He looks ready to ''murder'' the guy!
* ButtMonkey: Persistently conned, terrorized or mocked by the other animals in all his stories, even if he tends to get some vindication in the end.
* {{Cloudcuckoolander}}: Mistaken for one when he goes around talking to a flower, though he's actually talking to the Whos on the speck ''on'' the flower. He does have a few goofy imaginings in the movie, though.
* ElephantsAreScaredOfMice: Averted, since his best friend is a mouse.
* ElephantsNeverForget: Not only does he mention this trope, he has a PhotographicMemory.
* FamilyThemeNaming: In ''Wubbulous World'', his elephant bird son from ''Literature/HortonHatchesTheEgg'' is named Morton, and in the episode, "Horton Has a Hit", he is revealed to have an uncle named Norton.
* {{Forgiveness}}: [[spoiler:Quickly forgives Sour Kangaroo and offers her a cookie.]]
* FriendToAllChildren: He teaches some of the youngsters in the forest.
* GuardianEntity: Until he can prove to Nool the Whos exist, he's the only thing between them and utter destruction.
* GentleGiant: A huge elephant with an even bigger heart (metaphorically, of course). To the nanoscopic Whos this makes him gargantuan.
* GoodParents: In ''Wubbulous World'', he is shown to care a lot about Morton, his elephant bird son from ''Literature/HortonHatchesTheEgg''. Many episodes show him teaching Morton welcome life lessons and trying to make him happy.
* HeterosexualLifePartners: Is best buds with Morton and Ned.
* HonorableElephant: And he's faithful 100 percent.
* LargeHam: When Jim Carrey plays him naturally. Also considering the size of the character, it adds the goofball version of Horton's rather LARGE personality.
* MadLibsCatchphrase: His catchphrase is "I meant what I said and I said what I meant, ----- 100%".
* MrImagination: In the movie, he's prone to having daydreams about being a spy or an anime character.
* NiceGuy: His heart is as huge as him.
* ProtagonistTitle: "'''Horton''' Hears A Who".
* ShakingTheRump: Shakes his butt at one point in the 2008 movie.
* SimpletonVoice: Kent Rogers essentially uses his Beaky Buzzard voice for his take on Horton in the Merrie Melodies adaptation of ''Horton Hatches An Egg''.
* UndyingLoyalty: "And an elephant's faithful 100 percent."
* WhyDidItHaveToBeSnakes: Is shown to be scared of spiders in one episode of ''Wubbulous World'', though gets over it when he takes pity on a friendlier case.
[[/folder]]

[[folder:Jane/The Sour Kangaroo]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/horton_hears_a_who_pics_horton_hears_a_who_19717288_1280_688.jpg]]
-->'''Voiced by:''' Creator/JuneForay (1970 TV Special), Stephanie D'Abruzzo (''The Wubbulous World of Dr Seuss''), Creator/CarolBurnett (2008 animated film)

The book's main antagonist, she thinks that Horton is a fool for thinking that there is life on a speck of dust.
----
* AdaptationalKarma:
** Downplayed in the 2008 film, where the rest of the animals briefly shame and overrule her when the speck indeed turns out to be populated. She is still EasilyForgiven by [[AllLovingHero Horton]] however.
** Usually played straight in ''Wubbulous World'' where most of her worst moments result in her becoming TheChewToy or being forced to make amends.
* AdaptationalNiceGuy: In ''Wubbulous World''. Though she's still pretty conceited, she's generally much nicer towards Horton, and her antagonistic moments are more mundane or accidental with her often repenting. This is likely due to the series taking place after ''Hears A Who''.
* AdaptationalVillainy:
** The 2008 film by contrast makes her a far more short-tempered tyrant, with Horton not her only target of abuse, and while she does undergo the same HeelFaceTurn after discovering about the Whos, it's not before she tries to hide the truth from the other animals to save face.
** Both animated adaptations promote her to TheQueenpin of sorts, spearheading or enlisting all of the other animals to turn on Horton, while in the book she is seemingly only another heckler in the jungle, with the others working on their own accord until their last resort.
* AmazingTechnicolorWildlife: She's coloured into a yellow kangaroo in the 1970 special and ''Wubbulous World'' TV series. She's purple in the 2008 film.
* AntiVillain: She commits villainous acts like child abuse (upon her son and other children) and attempted to destroy Horton's clover, only out of her belief that Horton is insane and that she is doing so for the well-fare of the animals of Nool and the safety of the children. See ObliviouslyEvil below.
* AscendedExtra: She only appeared as an antagonist in one Seuss book, though a lot of adaptations like using her prominently. In ''Wubbulous World'' in particular she appears in several stories, a few of which she is the main character.
* TheAtoner: [[spoiler: Becomes co-guardian of the Whos with Horton in the ending]].
* BigBad: An unintentional example. She sees Horton's belief that a tiny civilization being real is absurd and tries to destroy the speck at various points. [[spoiler:But once she realises that Horton was right, she is deeply ashamed of what she almost did.]]
* ContrastingSequelAntagonist: Both [[Literature/HortonHatchesTheEgg Mayzie the bird]] and [[Literature/HortonAndTheKwuggerbugAndMoreLostStories the Kwuggerbug]] were mean spirited con artists who took advantage of Horton's good nature and paid for it. Jane by contrast is a WellIntentionedExtremist hell bent on separating Horton from his supposed delusions of Whos, only to repent when she realises her error.
* ControlFreak: The 2008 version seems more obsessed over her authority over Nool and Horton undermining it. When the Whos are revealed to everyone and she is proven wrong, she has an understated VillainousBreakdown.
* CurtainsMatchTheWindows: In the 2008 film she has purple fur and purple eyes.
* TheDreaded: Most of the other animals cower and run before her in the 2008 movie. [[OhCrap She realises she has truly lost]] when this ends and they turn their back on her when Horton is proven right.
* EarlyBirdCameo: A very similar looking kangaroo and her joey are seen laughing at Horton in ''Horton Hatches An Egg''.
* EasilyForgiven: She attempted to commit genocide of the Whos on the clover and she is easily forgiven by Horton and the other animals for her villainous acts.
* ExpressiveEars: Her ears droop down in sadness when the whole community of the Jungle of Nool (sans Horton) isolate her.
* FantasyForbiddingMother: Doesn't want Rudy to join in the "speck nonsense".
%%* HaughtyHmph: Just like in the book, she belts out quite a few of these when she hears Horton's ridiculous stories about microscopic people.
* HeelFaceTurn: [[spoiler: Becomes co-guardian of the Whos with Horton in the ending]].
* {{Hypocrite}}: Despite constantly proclaiming ThinkOfTheChildren, she seriously considers feeding her own son to a carnivorous vulture in order to defeat Horton.
* InSeriesNickname: Is known as "Sour Kangaroo".
* KarmaHoudini: Out of the three antagonists in the Horton books, she is the only one to not receive a comeuppance of any kind, though at least has a HeelRealization in the 2008 movie. Subverted in ''Wubbulous World'', where most of her worst actions backfire onto her or lead to a remorseful moment.
* MamaBear: She is very protective of Junior in ''Wubbulous World''. She ''believes'' she is this to Rudy in the 2008 movie, though [[JerkAss it's debatable]].
* MeaningfulName: More like "meaningful nickname" thanks to her sour disposition on things.
* MyGodWhatHaveIDone:
** [[spoiler:She's truly ashamed of herself when she realizes that she almost destroyed an entire civilization.]]
** Said word for word in the ''Wubbulous World'' episode "The Muckster" when she accidentally commands the title device onto Junior.
* NamedByTheAdaptation: She only goes by the moniker "the Sour Kangaroo" in the original book. She is named Jane in the 1970 special, which carries over into some other works like ''Wubbulous World''.
* NeatFreak: Her ''Wubbulous World'' characterisation. "You can ''never'' be too clean".
* ObnoxiousEntitledHousewife: Most incarnations depict her as argumentative and a ControlFreak both towards the jungle and towards her child. This is most evident in the 2008 film, where she insists on keeping her son "pouch-schooled," and invokes ThinkOfTheChildren to rally everybody against Horton for believing something out of the ordinary.
* ObliviouslyEvil: In all interpretations, she really doesn't know that the speck is an entire civilization and just wants to keep order in Nool. [[spoiler:She later comes to regret her actions.]]
* SanitySlippage: Averted. She almost starts to lose it when the Wickersham brothers refusing to trust her, but completely calms down when [[ShamedByAMob the animals of Nool pull the "shame on you" face on her and isolate her]].
* SmugSnake: Both adaptations convey her as incredibly pompous and obsessed with proving her scepticism about the speck is correct. This is demonstrated vividly in the 2008 film where she offers Horton a chance out if he directly admits she is right, and even when she is disproven makes a final desperate attempt to cover it up, reduced to a whimpering shell when she realises no one is listening to her anymore.
* UnwittingInstigatorOfDoom: Almost destroys Whoville and all its inhabitants, assuming it is merely an unimportant speck. This role is repeated in several instances in ''Wubbulous World'', where her lack of foresight or vanity keeps accidentally causing problems.
* VillainousBreakdown: Through the 2008 movie. She already starts with a [[TranquilFury very thinly contained temper]], but the more Horton persists with the speck, the increasingly more vicious and maniacally desperate she gets in getting rid of it. When she is finally disproven however, and the other animals refuse to listen to her, she is reduced to deflated whimpering wreck.
* WellIntentionedExtremist: Jane goes to incredible lengths to dispose of Horton's speck, though genuinely because she thinks it's delusional and needs to be dispelled. When the Whos are proven to be real, she accepts Horton is right and helps take care of them. Leans a bit more into NotSoWellIntentionedExtremist in the 2008 movie, where she is a ControlFreak fuelled more by ego and spite, even if she does still repent in the end.
[[/folder]]

[[folder:Junior/Rudy Kangaroo]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/horton_who_disneyscreencaps_com_3606.jpg]]
-->'''Voiced by:''' Creator/ChuckJones (1970 TV Special); Creator/JoshFlitter (2008 animated film)

Sour Kangaroo's son.
----
* AdaptationalNiceGuy:
** He is shown to have a much nicer disposition compared to Jane in the 2008 movie.
** Zigzagged in ''Wubbulous World'', he's still a YesMan to Jane, but shares her redeeming qualities, and is also friends with Horton's son.
* AmazingTechnicolorWildlife: Like his mother, Rudy is a purple kangaroo.
* AmbiguouslyAbsentParent: His dad is never seen.
* AdaptationalPersonalityChange: In the book, the joey willingly agrees with Sour Kangaroo's belief that a civilization cannot exist on a tiny flower. In the film, the joey (named Rudy here) is more accepting of Horton's assertions, and does not like it when his mother (named Jane here) accuses Horton of being crazy.
* BigDamnHeroes: Rudy jumps in to save the clover, just before it falls into the pot of oil.
* MommasBoy: {{Invoked}} by his bossy mom who always keeps Rudy in her protective pouch. [[spoiler:Until the end.]]
* MoralityPet:
** {{Zig Zagged}} in the 2008 movie. Rudy does make Jane look more understandable, but his presence doesn't stop her from going after Horton.
** Played more straight in ''Wubbulous World'' where in spite of her still-evident snobbishness, Jane is unambiguously loving towards Junior.
* NamedByTheAdaptation: Rudy in the 2008 movie. Junior in the 1970 special and some other works.
* StrongFamilyResemblance: A small, male version of Jane.
* YesMan: To his mother in the books and most adaptations. Subverted in the 2008 movie.
[[/folder]]

[[folder:The Wickersham Brothers]]
A troop of monkeys sent to steal Horton's clover.
----
* AdaptationalDumbass: Their ''Wubbulous World'' incarnations tend to be depicted as clumsy louts who talk in HulkSpeak.
* AdaptationalVillainy: In the original book they are largely just mischievous fellow cynics who try to get rid of the clover along with the other animals. In the 2008 movie, they are conveyed as more sadistic thugs (if not to quite the same level exaggeration as the kangaroo and Vlad).
* EvenEvilHasStandards: In the 2008 movie. While far more sadistic and eager to harm Horton, when they discover the Whos are real and they almost unknowingly killed an entire civilisation, they instantly back down from their job and refuse to obey the Sour Kangaroo, even shooting her one hell of a DeathGlare.
* PunchClockVillain: Most adaptations interpret them as mooks hired to do the kangaroo's dirty work. Jane sometimes re-enlists them in ''Wubbulous World'' though they also sometimes do grunt work for other characters such as Yertle the Turtle.
* PsychoForHire: PlayedForLaughs in the 2008 movie. Not as blatantly as Vlad (as he himself insists), but they clearly enjoy their work, and even express disappointment when the kangaroo suggests a less harmful approach if Horton cooperates. On the other hand, they still draw the line at ''mass genocide'' when the Whos turn out to be real.
[[/folder]]

[[folder:Vlad Vladikoff]]
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/imglgqrd9.jpg]]
-->'''Voiced by:''' Creator/WillArnett

A vulture hired by the Sour Kangaroo to steal Horton's clover.
----
* AdaptationalNameChange: Is named Whizzer [=McWhoff=] in one cartoon version of the book.
* AdaptationalVillainy: In the book he's just another accomplice for the Sour Kangaroo, while in the 2008 movie he is a gleeful PsychoForHire that wants to make a snack out of Rudy as payment.
* AdaptationSpeciesChange: He was an eagle in the book, but 2008 film changed him to a vulture.
* AlliterativeName: '''V'''lad '''V'''ladikoff.
* BruiserWithASoftCenter: Is genuinely touched by Horton's defense of the Who's, and he openly weeps when Horton and Sour Kangaroo make up.
* BunnyEarsLawyer: Despite his obvious instability, he's the only antagonist who manages the get the clover out of Horton's grasp. This includes the mob of Wickersham Brothers.
* DarkIsEvil: A giant vulture with black and grey feathers in the film, although he was an eagle in the book his plumage was still very dark.
* EvilIsHammy: In the film, he's prone to overdramatic dialogue to make himself look more sinister. His accent helps too.
* HeelFaceTurn: Seems to go through this on seeing Horton's forgiveness since he gets teary-eyed over the happy resolution.
* LaughablyEvil: His hamminess certainly makes him funny at certain points. Particularly when he shows his inferiority complex when the Wickersham Brothers are brought up, or the slapstick he is involved with during his first encounter with Horton.
* OneSteveLimit: There are actually two Vlads in the movie: This Vlad, and a bunny who makes cookies.
* PsychoForHire: He is hired by Jane Kangaroo to get rid of the clover, and seems to enjoy it.
* ToothyBird: Has a set of sharp teeth.
* VileVulture: He's a sinister, creepy vulture who wants to eat Rudy.
* WouldHurtAChild: Possibly, given how he would do Kangaroo's work if she gives him Rudy.
[[/folder]]

[[folder:Morton the Mouse]]
[[quoteright:239:https://static.tvtropes.org/pmwiki/pub/images/mv5bmja0nzqxmja0of5bml5banbnxkftztcwmjuxnze2mq_v1_sx640_sy720.jpg]]
-->'''Voiced by:''' Creator/SethRogen

Horton's best friend in the Jungle of Nool.
----
* AmazingTechnicolorWildlife: He's a blue mouse.
* BlueIsHeroic: Morton is a blue mouse and [[spoiler:is the only one of Nool to stand up for Horton.]]
* CanonForeigner: Appears only in the 2008 movie.
* CurtainsMatchTheWindows: Has blue fur and blue eyes.
* DeadpanSnarker: Comes with being friends with a guy like Horton.
* HeterosexualLifePartners: With Horton; Mort openly defends him from accusations of being a crazy and/or bad guy.
* NiceGuy: Despite being just as skeptical about the tiny world Horton talks about, Morton is the only one to defend his friend from Sour Kangaroo's accusations of the elephant being crazy.
* NiceMice: He is a mouse and a loyal buddy to Horton, albeit a sarcastic one.
* SuperSpeed: He's one fast mouse.
[[/folder]]

[[folder:Katie]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/b40a2f758834a9a550daedd3c12381e8.jpg]]
-->'''Voiced by:''' Joey King (2008 animated film)
Katie is known throughout the movie "Horton Hears A Who," as the weird, annoying little fluff ball of joy.
----
* AmazingTechnicolorWildlife: She is a small yellow and orange baby yak.
* CanonForeigner: Only appears in the 2008 film.
* {{Cloudcuckoolander}}: She often does strange things including making sounds, walking backwards, sitting backwards and saying oquried things. Her imagination is out of this world and imagines that the little people living on her clover (like Horton and his Whos) are all ponies "who eat rainbows and poop butterflies".
[[/folder]]

[[folder:Tommy and Jessica]]
Two other students from the movie: a plump, orange creature and a bird.
----
* FatComicRelief: Downplayed for Tommy, whose size was the butt of ''one'' joke: him landing heavily on Horton's back.
[[/folder]]
!Whoville

[[folder:Mayor Nedd [=McDodd=]]]
[[quoteright:300:https://static.tvtropes.org/pmwiki/pub/images/mayorwhoville.jpg]]
-->'''Voiced by:''' Creator/SteveCarell (2008 animated film)

The mayor of Whoville. He has 96 daughters, 1 son named [=JoJo=] and his wife Sally.
----
* AbledInTheAdaptation: Downplayed. In the original book and in the 1970 special, he is shown to wear glasses. This is not carried over to the 2008 animated film.
* AdaptationalAngstUpgrade: PlayedForLaughs in the 2008 movie, where he suffers a FreakOut upon first learning how his world exists with Horton's (aka. "the one holding the speck").
* AdaptationalDyeJob: His hair is uncoloured in the book, brown in the movie, and white in the cartoon.
* AdaptationalJobChange: Is usually the mayor, but in the cartoon, he is a science professor.
* AdaptationalNameChange: Is named Dr. Whoovey in one cartoon version of the book.
* BlueIsHeroic: Wears a blue fur-suit without sleeves and is the deuteragonist.
* {{Cloudcuckoolander}}: To the same extent as Horton. He's described as odd even in his character introduction.
%%* {{Deuteragonist}}: To Horton's protagonist.
* HappilyMarried: With Sally O' Malley; they seem to have a stable marriage and she's patient even when he's acting crazy.
* NamedByTheAdaptation: In the 1970 special, he is named Dr. Hoovey (and is also downgraded to a science professor) and is named Ned [=McDodd=] in the film.
* NiceGuy: "Devoted, fair, and a little bit odd".
[[/folder]]

[[folder:Sally O' Malley]]
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/sally_o_malley_by_08newmanb_d6uzkzu.png]]
-->'''Voiced by:''' Creator/AmyPoehler

Ned's wife and mother to [=JoJo=] and 96 daughters.
----
%%* DeadpanSnarker: A pointed example.
* FieryRedhead: {{Averted}}. Sally is probably the most sane Who in Whoville.
* HappilyMarried: With Ned, she's relatively patient with him.
* MaidenNameDebate: It appears that she didn't take Ned's last name.
* NiceGirl: Sally is an overall sweet and devoted person.
* OnlySaneWoman: Especially when it looks like her husband is going off the deep end.
[[/folder]]

[[folder:Dr. Mary Lou [=LaRue=]]]
[[quoteright:210:https://static.tvtropes.org/pmwiki/pub/images/char_32761.jpg]]
-->'''Voiced by:''' Creator/IslaFisher

A teacher at ''Who U.''
----
* AbsentMindedProfessor: Can be a little scatterbrained.
* CurtainsMatchTheWindows: She has light purple hair and purple eyes.
* DitzyGenius: The smartest person of the staff at Who University, who's also somewhat scatterbrained.
* LabcoatOfScienceAndMedicine: Wears a lab coat and is a scientist.
* SpeechImpediment: Dr. [=LaRue=] has an audible lisp.
* WhatHappenedToTheMouse: She appears in exactly three scenes in the movie, and there's nothing much of her character development. This despite the fact that, until Vlad dropped the clover into the clover field, she was the only other Who besides the Mayor to understand the truth about their world. She notably doesn't even come to the Mayor's defense when he's being mocked for his claims.
* WorldOfTechnicolorHair: Dr. [=LaRue=] has light purple hair.
[[/folder]]

[[folder:[=JoJo=] [=McDodd=]]]
[[quoteright:206:https://static.tvtropes.org/pmwiki/pub/images/2143509206_60332b8570.jpg]]
--> '''Voiced by:''' [[Music/JesseMcCartney Jesse McCartney]]

Ned and Sally's only son and eldest child. He's next in line for being the Mayor of Whoville.
----
* AdaptationalBadass: The book only showed him as the last resort to save Whoville. And while he still is the one to save Whoville in the animated adaptation, he also becomes a GadgeteerGenius.
* AscendedExtra: In the book, he was brought in as a last resort to save Whoville. In the movie, he's a much more prominent character and in the Seussical, he's the protagonist.
* BigLittleBrother: He is the next mayor because he is the oldest, but he is smaller than all of his sisters.
* BrainyBrunette: Of the making music variety. He is smarter than he looks and is capable of making musical instruments out of discarded various objects.
* BreakoutCharacter: Jojo quickly became the most popular character in the film adaptation.
* ComicallySerious: He is this many time to his father's antics in Whoville.
* DarkIsNotEvil: His color schemes are black and white and he's the tritagonist.
* EmoTeen: A sullen, apathetic boy in dark clothing who's so terrified of disappointing his father that he never speaks.
* GadgeteerGenius: [=JoJo=] filled the abandon observatory with castaway items and set up an elaborate system to produce music.
* {{Goth}}: Jojo shows some shades of this.
* GothsHaveItHard: Jojo, who wears dark clothes, keeps to himself and is pressured to be the next mayor one day. Something he doesn't want, but he is too scared of possibly disappointing his father.
* HiddenDepths:
** "But he's anything but silent. He hears music in the tapping of an old keyboard, feels the beat in the rhythmic bounce of a basketball and finds harmony in wind whistling over a comb."
** The ending shows that [=JoJo=] has a great singing voice.
* OddNameOut: Ninety-six of the Mayor's ninety-seven children all have names beginning with the letter H. Jojo, the Mayor's only son, is the Odd Name Out.
* OnlySaneMan: Jojo to the antics going on in Whoville.
* TheQuietOne: He only has four lines in the entire movie.
* RelatedInTheAdaptation: In the original book the Mayor and Jojo are unrelated. Here, they are father and son.
* ResentfulOutnumberedSibling: He has 96 sisters and is the only son in his family.
* SkywardScream: Uses this to save everyone in Whoville by shouting, "YOPP!".
* SuddenlySpeaking: Jojo shouts "YOPP!", and finally speaking for the first time.
* {{Tritagonist}}: To Horton's protagonist and his father's {{Deuteragonist}}.
* WellDoneSonGuy: "[=JoJo=] is so worried that he'll say something to disappoint his father that he finds it best not to speak- ever."
* UnlikelyHero: Although you can see it coming a mile away, the mopey, silent Jojo is, of course, the one who comes through in the end.
[[/folder]]