Because of the show's longevity, many characters have appeared throughout the show, each with a wide array of personalities and other character traits. The following describes characters from the picture books and animated television series by Marc Brown:


[[folder:Common character tropes]]
* BookDumb: Depending on the writer, any one of Arthur's immediate friends (except Brain), Arthur himself, or even the grown ups may be subject to this.
* {{Bookworm}}: Every child character in the show has been seen in the library at least once.
* ButNotTooForeign: Do any of the characters [[AmbiguouslyBrown appear to be their ethnicities or nationalities]]? Then again, they are anthropomorphic animals...[[FurryConfusion Or are they?]]
* CartoonCreature: One of the commonly asked questions about the show is the subject of which animal some of the characters are. Arthur and his family are the most confusing since they do not look like aardvarks at all.
** Prunella is another character that's debated upon; it is undecided on whether or not she is a poodle or a rat. PBS says she's a rat but Marc Brown says she's a poodle.
* FreeRangeChildren: Arthur and co. are about only eight years old and are in third grade, yet they run all about Elwood City much like teens several years older. None of their parents seem to be concerned, with the exception of what happens in S2's "Lost!" where Arthur accidentally rides the bus line to the city limits.
** PlayedWith in an episode where for some reason, Brain and Binky think they're trapped at the soccer field and their moms forgot to pick them up. They go everywhere else in their neighborhood, but can't walk home?
** CloseKnitCommunity: This may be the best explanation; some episodes imply that the parents in Mr. Ratburn's class have all shared contact information with each other, while others make it clear that some of the parents are on a FirstNameBasis.
* GoodParents
* ItsTheBestWhateverEver[=/=]WorstWhateverEver: Many of the show's characters have webpages detailing such experiences.
* LimitedWardrobe The characters all have characteristic outfits by which they are identified. Depending on the episode or the setting, they may be changed.
* LivingProp: There are a number of such characters in Arthur, mostly recurring townspeople and the students in D.W.'s class. Of important note are a pair of rabbit kids who've been in Arthur's class since the S1, but are not as developed as their classmates (in 15 seasons, the male one has only talked twice, and the female one ''never!''). S13's "[=MacFrensky=]" had a class list with the names Alex & Maria on it, but some fans refuse to believe those are their names, since Arthur has had several other one-shot classmates over the years (never mind that the two rabbits were the ''only other two kids besides the already named regulars shown in class in that episode'').
** It was confirmed at New York Comic Con 2013 that the two rabbit kids are indeed named Alex and Maria, and that the possibility of becoming Ascended Extras is open.
* NotAllowedToGrowUp: Even though some characters have birthdays over the course of the show, the characters are shown to never physically age, outside of occasional flash-forward or fantasy.
** Lampshaded by D.W. in S1's "Arthur's New Year's Eve", suggesting that she's trapped in some kind of time warp that causes her to never get any older.
* PunnyName: Most characters. The Crosswire family is probably the most obvious.
* [[RoundedCharacter Rounded Characters]]: One of the top reasons for the show's success.
** [[RenaissanceMan Renaissance Kids]]
* RotatingProtagonist
* SpeciesSurname: Averted. See below.
* TrademarkFavoriteFood: Very subtle, but just about EVERYONE on this show likes snacking on popcorn.
** There's a trademark favorite drink, at least in earlier seasons anyway, for the Read family. They are almost always seen drinking milk at meals.
* WiseBeyondTheirYears: A number of characters, from D.W.'s friend Emily to Arthur and his friends. They're not your average third-grade kids, after all.
** One of the best examples is D.W. and her zany BatmanGambit to trick Arthur and The Brain to take her to the science exhibit in S4's "Prove It!", ''and it worked.''
* ZanyScheme

[[folder:3rd/4th grade cast]]

!!'''Arthur Timothy Read'''

The title character of the show. He and his family members are aardvarks, though it is not obvious due to the lack of elongated nostrils.
* {{Adorkable}}: For a third grader, anyway.
* ArtEvolution: Applies to the book version, where he starts out as an actual aardvark (looking more like an anteater), and would slowly change in design until he came to his current look.
* BewareTheNiceOnes: Normally a good-natured NiceGuy, but it's ''not'' a good idea to anger him. When D.W. destroyed his model plane and chose to blame him instead of apologising for her actions, he ''erupted''.
* BigYes: When he finds out that Buster is coming home from a LongBusTrip with his father in S3's "Buster's Back".
--> *Answering the phone* Hello? Yeah. Yeah? '''YEAH!'''
* BowTiesAreCool: The Modus Operandi for his formal attire.
* ButtMonkey: Would become one in later seasons.
* CatsAreMean: Was a firm believer of this, as exemplified in "Francine and the Feline (S3)"; as of "D.W.'s Furry Freak-Out (S12)" however, he seems to not mind them anymore.
* CharacterBlog: The Arthur Facebook page.
* CharacterTics: Arthur fiddles with his glasses when he's lying.
* CrazyConsumption: D.W., when imagining Arthur in a negative light, sometimes has him digesting cake either in one bite or in a mess.
** In "D.W. Gets Lost" [[spoiler: this actually does happen.]]
* CrowdChant: Arthur gets one when he is cleared for embezzlement in "Arthur Accused!"
* DeadpanSnarker:
--> '''DW:''' Where were you between six months ago and yesterday?
--> '''Arthur:''' Listening to you whine about the snowball 24 hours a day.
* EyeGlasses
* TheEveryman: In sharp contrast to a group of widely varied friends with telling character traits. Lampshaded in S6's "Best of the Nest", when Arthur settles on "Just Plain Goose." This is extremely poignant when one considers that most of the later season's episodes focus less on Arthur.
* EyeCam: Almost all of "You Are Arthur".
* {{Facepalm}}: A very brief one after [[DramaticDrop dropping the wedding ring]] in "D.W. Thinks Big".
* FullNameUltimatum: Unlike D.W., he has only ever been issued one once throughout the show in S4's "Arthur's Big Hit", and it is lampshaded.
-->'''Mrs. Read''': Arthur Timothy Read, come here!
-->'''Arthur''': Uh-oh, middle name.
* GameShowAppearance: Arthur winding up on in-universe ''Riddle Quest'' in S5's "Arthur and the Big Riddle".
* GuiltyPleasures: Arthur is secretly a fan of in-universe toddler's show "Love Ducks". He keeps it a secret because (per the title of the S4 episode) "That's a Baby Show."
* {{Headdesk}}: He is so exhausted from PanderingToTheBase in S1's "Arthur Writes a Story" that he does a Double Headdesk.
* TheHero: As the title character and de facto leader of his friend group.
* HeterosexualLifePartners: With Buster.
* HypocriticalHumor: He accuses his friends of "not being able to stand a little competition" when playing games with them in "Arthur the Loser". In this episode he resorts to cheating against all of his friends because he proved to be a SoreLoser before his scheme was uncovered.
* IdiotBall: " So Funny I Forgot to Laugh" represents such a moment of weakness for Arthur that it's unconvincing.
** Arthur's cost cutting ideas in Arthur Read Super Saver" are more likely to come from the four-year-old-cast, like bathing in water from the Molinas' sprinklers, or trying to cut his family's water bill by getting a Pal to lick food stains off the flatware.
* JerkassBall: Happens to him [[DependingOnTheWriter at times]].
* MusicalisInterruptus: The teaser for "That's a Baby Show!" has Arthur demanding a stopdown when Mary Moo Cow and co. randomly show up in his bedroom.
* NeverLiveItDown: His aforementioned cheating in "Arthur the Loser" and his underwear incident; being accused of stealing D.W.'s snowball also counts.
* NiceGuy
* OfficialCouple: He is shown married to Francine in the future on multiple occasions, despite massive denial between each other in S2's "Arthur and the Square Dance".
* PinocchioNose: Has an all-too-obvious habit of fiddling with his glasses when he lies.
* ThisLoserIsYou: Arthur could be described as this, DependingOnTheWriter.
* WouldHitAGirl: "Arthur's Big Hit". That's all we have to bring up.
* YoureInsane: Arthur to D.W. after the latter announces plans to live with Mary Moo Cow in S5's "The Last of Mary Moo Cow".
** !!'''Buster Baxter'''

Best friend of Arthur. He and his divorced parents are rabbits.

* AgainstMyReligion: In S7's "Buster's Amish Mismatch" when he became Amish after a field trip.
* AgentMulder: Firmly believes in the existence of aliens.
* AlliterativeName
* AmateurSleuth: One of Buster's trademarks, often imitating hard-boiled PrivateDetective stories when he's on a case.
** ClearMyName: "Arthur Accused!"
* BeCarefulWhatYouWishFor: The teaser for "Arthur's Substitute Teacher Trouble" ends with Buster wishing that Mr. Ratburn would disappear.
* BigEater: So much so that during a fantasy sequence in S3's "I'd Rather Read it Myself", D.W. imagines him as a robot that only exists to eat. One wonders just how the kid can stay lean. Often leads to CrazyConsumption.
* {{Cloudcuckoolander}}: Extremely superstitious, and is very, VERY obsessed with extraterrestrial life.
* EarsAsHair: Buster's mother makes him wear an embarrassing shower cap when he goes swimming, but his ears are more prominent than most, and it would be dangerous to get water inside of them.
* EurekaMoment: How Buster usually solves his cases. "Overflowing?" "That song!"
* ExpressiveEars: They droop when Buster is upset. If "Buster Makes the Grade" is any indication, he doesn't take school exams seriously.
* HeterosexualLifePartners: With Arthur.
* HypnoFool: In S11's "Buenas Noches, Vicita", one of D.W.'s friends (Vicita) can't go to sleep. D.W. tries several methods, including trying to get Buster to hypnotize her to sleep. A couple of seconds later...
* {{Keet}}: He's the most energetic and funniest of Arthur's friends.
* TheLancer: A position shared with Francine.
* LittleKnownFacts: Buster will believe anything he reads on the internet, as shown in S9's "Buster the Myth Maker".
* MeaningfulName: Buster's street address is 7 Roswell Court. An alien spaceship is rumored to have crashed in Roswell, New Mexico.
* NotSoDifferent: With, of all characters, Mr. Ratburn. They seem opposites in most respects, especially in regards to anything school-related. Buster has a (rather silly) fear of his teacher's love for learning. Despite this, the characters share many other definitive personal tastes. The biggest examples? Both obsessively love desserts, both watch cartoons, and Mr. Ratburn seems to have been much more like Buster in his youth according to what was seen on an old videotape from his high school days.
* {{Nerd}}: His aforementioned obsession with extraterrestrial life.
* PutOnABus: S2's "Arthur's Faraway Friend" has Buster leave the show to travel the world with his airline pilot father. TheBusCameBack at the start of S3.
* StrangerInAFamiliarLand: The main plot points of S3's "Buster's Back" and "The Ballad of Buster Baxter".
* TerrifiedOfGerms: Plot point of S11's "Germaphobia".
* WildTake: In his nightmare in S1's "Arthur's First Sleepover".

!!'''Francine Alice Frensky'''

2nd best friend of Arthur. She and her family are monkeys.

* TheAce: Exceptionally good at almost every sport that exists, always has the last word with some witty or sarcastic reply, and is usually the one that ends up having to bail out one or all of her friends in some way or another.
** It should be noted, though, that she might not be so good at badminton or skiing, if "The Good Sport" is any indication. Once she befriends Jenna, she will play badminton, but previously said it was "for wusses."
* AlliterativeName
* AmazinglyEmbarrassingParents: Oliver Frensky. Francine imagines this in "My Dad, the Garbage Man", and she feels the need to apologize for her father's enthusiasm in "Arthur Cleans Up".
* AmbiguouslyBrown: Many people pictured Francine and her family as being rather dark-skinned or even black, but considering that they're Polish Jews...
* ArtEvolution: In the first few books she wore dresses and her muzzle didn't blend into her face, making it more obvious she's a monkey.
* BerserkButton: Beating her in anything sports related.
** "A ''griffin''. A ''griffin''. A ''griffin''..." Note that this was in an ImagineSpot in S1's "Meek for a Week", showing what would happen if Francine kept her anger bottled up for too long.
** Insulting Hanukkah also qualifies, as seen in the Christmas special.
* BreakTheHaughty: Francine has needed a little attitude adjustment from time to time when she gets a little too abrasive.
* BrownEyes
* DeadpanSnarker
* EatingLunchAlone: Muffy lets her take the heat for cheating on a math test in "Arthur and the True Francine". Francine is too despondent to sit with company.
** CrowdChant: Muffy confesses, and Francine is cleared to play in a baseball game with her relieved teammates.
* FemininityFailure: She tries to be feminine for one day, picture day, where she goes to school in a dress and doesn't play kickball during recess so she'll be presentable for her photo, but she ends up playing anyway, and being scruffy in the picture.
* HeterosexualLifePartners: With Muffy.
* HollywoodToneDeaf: Subverted by the end of S4's "To Beat or Not to Beat"; she isn't a bad singer, she just can't sing and drum at the same time.
** Although in later seasons, she would become a much better singer, and her drumming would rarely if ever be mentioned or seen.
* HypocriticalHumor: Francine often criticizes other people for being mean, despite being a textbook example.
* JerkJock: She gives off vibes of this, though she's not that bad.
* JerkWithAHeartOfGold: Depending on the writer, as there are plenty of episodes where Francine is not a jerk.
* TheLancer: Shared with Buster.
* OfficialCouple: She is shown married to Arthur in the future on multiple occasions, despite massive denial between each other in S2's "Arthur and the Square Dance". She insisted on doing the rescue scene in "Arthur Makes a Movie" and was keen to play spin the bottle at Arthur's birthday party, possibly in the hope of getting to kiss Arthur.
* PassionateSportsGirl: Francine is very athletic and loves sports, especially soccer, football, kickball, and bowling. The only sports she doesn't excel at are badminton and figure skating (which she dismisses as "girly"). Francine is very determined, perhaps even restless, and if she doesn't have an immediate knack for a certain sport or skill, she can become frustrated.
* PrimaDonnaDirector: In S1's "Francine Frensky, Superstar".a
* SlobsVersusSnobs: Between her and Muffy.
* SoreLoser: One of her longtime trademarks; taken to new heights in "Arthur Calls It", where she berates Arthur for outing Buster in a baseball game in a play that was obscured to most observers and tries to discredit him, all because she was angry they had lost.
* StockPunishment: The teaser for "Francine's Pilfered Paper" takes place in the Puritan era, and she is punished for plagiarism in this way.
** AddedAlliterativeAppeal: A book in a bad dream that Francine has is entitled "Francine Frensky: Fraud!".
* TokenMinority: Francine's family is Jewish in an apparently mainly Christian community.
* TomboyAndGirlyGirl: Her and Muffy.
* {{Tsundere}}: Comes off as this occasionally, especially towards Arthur.
* TyrantTakesTheHelm: Main plot point in S1's "Francine Frensky, Superstar". Only after Mr. Ratburn intervened (after what amounted to the entire class sabotaging the play rehearsal) was everything put back into place.
* WeWantOurJerkBack: Happens in S1's "Meek For A Week"', which nearly caused the group's team to lose a hockey match. They got the jerk back when her BerserkButton was pushed.
* WithFriendsLikeThese: Her and most of the cast, but it is more prominent between her with Muffy.
** Sort of goes both ways with Muffy, considering the latter is so often a RichBitch, and appears totally clueless as to why Francine doesn't have the same amount of money or cool gadgets that she does--among other things Muffy is clueless about.

!!'''Mary Alice "Muffy" Crosswire'''

Best friend of Francine, since her arrival in 2nd grade. Like the Frensky's, she and her family are monkeys.

* AesopAmnesia: Muffy's lessons in selflessness never seem to last more than an episode.
** Lampshaded in "Muffy's Art Attack", where she tried to take credit for a series of sculptures that were actually handcrafted by Bailey, just as she took all credit for the cookie recipe she and her friends made in "How the Cookie Crumbles"; Francine does not let this go unnoticed.
* AlphaBitch: Muffy is often a stuck-up and a complete showoff who does not care to see things from other people's perspectives. She is even cruel to her friends from time to time.
** LovableAlphaBitch: However, she learns from her mistakes and she can be a nice girl.
* ArtEvolution: Originally drawn with buck teeth.
* BigFancyHouse: A sign of her unknowingly vast wealth, to the point where it actually has a ''mini amusement park'' inside of it.
* BitchInSheepsClothing: When she was first introduced in the main cast in S1's "Arthur and the True Francine".
* BreakTheHaughty
* CatchPhrase: "Vomitrocious!"
* ChainOfDeals: Utilizes a small one to get her hands on a World Girl doll in "Cents-less".
* TheChick: The most traditionally feminine of the main group.
* TheClan: Part of a family that is shown to be influential in the transportation industry.
* TheFashionista: Mostly in episodes where she has an opportunity to be in other clothes besides her standard dress.
* {{Flanderization}}: Her (claimed) marketing knowledge.
* GreenEyes
* HeterosexualLifePartners: With Francine.
* HypocriticalHumor: Muffy regularly accuses people of being snobs despite being the textbook example herself.
** Also her catchphrase, "How rude!", usually spoken in a condescending manner or when she herself is doing something most would also consider rude.
* IntergenerationalFriendship: In "The Butler Did... What?", Muffy thought she had this kind of relationship with Bailey. But Francine points out she barely know him personally. To be fair to Muffy, the two are pretty close to one another before she got to know him better by the end of the episode.
** Later episodes show her ''trying'' to have a full version of this with Bailey, though her conversations with him still show shades of ego. For example, Bailey helps Muffy reconnect with her old imaginary friend--but first he has to reassure her she actually has imagination.
* JerkWithAHeartOfGold
* ItsAllAboutMe: Very much, but in later seasons, certain events have mellowed her at different times. For example, she's very upset when she realizes her desire for a bouncy house will result in [[spoiler: losing the cherry tree she's had since she was a kid.]] She also now helps out in a thrift store on occasion.
* [[ManipulativeBastard Manipulative Bitch]]
* MeaningfulName: Her street address is 1250 Nouveau Lane. Her family is Nouveau Riche, or new money, as explained below.
* NiceToTheWaiter: To her butler/chauffeur, Bailey.
* OnlyKnownByTheirNickname: Nobody, not even her parents, call Muffy "Mary".
** Although her mom did give her a FullNameUltimatum (Mary Alice Crosswire) in S1's "The Scare Your Pants Off Club".
* RichBitch
* RunningGag: Muffy tends to over pack during travel.
* SlobsVersusSnobs: Between her and Francine.
* TomboyAndGirlyGirl: Her and Francine.
* UpperClassTwit: In S13's "The Great [=MacGrady=]", it's shown that she literally ''does not know how'' to do dishes. She simply squirts some dish-washing liquid onto the sink full and expects that to do the job.
** When she learns her family history, she's actually shocked and disgusted when she finds out her family is not akin to royalty, but rather she's descended from commoners and most of her family's wealth comes from her dad's used car business.
** She thinks that using a credit card is not the same as spending money.
* WillNotTellALie: In the teaser for "Arthur and the True Francine" Muffy lies to her friends that she has never told a lie. The episode itself shows that [[BlatantLies she lied about a lot of things]] when she first came to Elwood City.
* WithFriendsLikeThese: Her and Francine.
** A particularly egregious example is in the episode "My Club Rules" where in Muffy basically decides [[LocalHangout the treehouse]] isn't good enough for her and that she'll start her own club. Muffy basically begins a chain of everyone acting like jerks to everyone else to go form their own clubs.
* YouHaveGotToBeKiddingMe: This is how Muffy responds when she learns that she has to go without spending money for a whole weekend.

!!'''Alan "The Brain" Powers'''

A young bear, and the smartest among Arthur's friends. Not to be confused with [[WesternAnimation/PinkyAndTheBrain that]] ''[[WesternAnimation/PinkyAndTheBrain other]]'' [[WesternAnimation/PinkyAndTheBrain 90's cartoon character named "The Brain".]]

* TheAce: Besides his intelligence, it is shown that he is also good at various sports. He and Francine are often partners for sport-centric episodes.
** Academics seems to come more naturally to him. Sports, he has claimed that he practices hard for.
* AmbiguouslyBrown: Brain is [[WordOfGod confirmed]] African-American but doesn't particularly look it since he's a bear.
** In later seasons, his mother is lighter furred than her son and husband, and is also blonde, meaning the Brain is possibly of mixed race. Then again she had brown hair originally, and as of season 16 is back to that, so it could be dyed.
* TheBartender: At his parents' ice cream shop in later seasons.
* TheBGrade: Brain gets a B- on a test in S9's "Breezy Listening Blues" and concludes that the breezy listening music his parents recently started playing in their music shop is having a deleterious effect on his studies.
* BigWhat: His reaction to his early demise in "Best of the Nest".
* [[SesquipedalianLoquaciousness Big Words]]: He was the one working on {{Antidisestablishmentarianism}} before the spelling bee in S1's "Arthur's Spelling Trouble".
* BlackBestFriend: Brain and Binky seem to be quite close, despite being polar opposites.
** ButNotTooBlack: His family's celebrating of Kwanza was the only indication of his race, until an African cousin comes over to visit.
* BlackAndNerdy
* BrownEyes
* ChildProdigy
* CloudCuckoolander: Certainly not as much as someone like Buster, but being the most ridiculously smart in the gang he occasionally will overthink and theorize things to ludicrous extremes, which usually just leaves everybody else bewildered.
* DependingOnTheWriter: Brain tends to range between TheSmartGuy who offers helpful information when needed, a StopHavingFunGuy who pops everyone's bubble, and a ChildProdigy who knows how to casually make things some scientists don't know how to make.
* KnownOnlyByTheirNickname: "The Brain" is only referred to as such by his peers.
* InsufferableGenius: Can slip into this at times.
* MrExposition
* NerdsLoveToughSchoolwork: The only one in class who doesn't groan when given a big homework assignment.
* NoNameGiven: It's not really considered appropriate for teachers to address students by their nicknames. Even though it was fudged at first, it was awkward. It didn't become a problem until the TV show began, both because the book narration is from Arthur's perspective and because it is in the third person. Circumstances were such that The Brain had to have a given name, and "Alan" is {{Adorkable}} without being difficult to swallow.
* OpeningShoutOut and InternalHomage: The latter of the two is an EpisodeTitleCard, shown in S3's "And Now Let's Talk to Some Kids".
* SanitySlippage: Brain is usually the most calm and approachable of all the kids, but when he feels he's been wronged in some way, he'll become darn near psychotic and start giggling crazily, trying to plot revenge.
* TheSmartGuy: A ChildProdigy par excellence.
* {{Technobabble}}
* TokenMinority: Brain and his Family seem to be the only major Black characters in the show.
* [[WhyDidItHaveToBeSnakes Why Did It Have To Be Water?]]: He was afraid to go to a pool party because of his aquaphobia, though later seasons remove it, implying that The Brain got over his fear.

!![[spoiler: '''Shelley''']] '''"Binky" Barnes'''

Another one of Arthur's friends, though also a bully, or once was anyway. He and his family are bulldogs. He plays the clarinet and also dances ballet. He hangs with a group called the "Tough Customers," though lately has somewhat drifted away from their ideals.

* AdultFear: Even if the concerns that Mrs. Barnes expresses in "Binky Goes Nuts" seem a bit excessive, they are realistic.
* AmbiguouslyGay: His HiddenDepths reveal an interest for stereotypically gay hobbies such as theater, dance (especially ballet), art, music, culture, and the likes.
---> "I like to read books with lots of pretty flowers. [[SuspiciouslySpecificDenial ...Being crushed by a giant pterodactyl!"]]
* ArtEvolution: In the books his ears were originally drawn flatter on his body and he was fatter.
* BerserkButton: NEVER speak ill of his mother, unless you want ice cream all over your face.
-->'''Buster:''' Your mother eats gym shorts!
-->'''Binky:''' '''''WHAT?!'''''
-->''(everyone is aghast at Buster's words as a very angry Binky proceeds to smash his ice cream sundae onto Buster's head)''
* BigBrotherInstinct: He's very nurturing and helpful with Mei-Lin.
* TheBigGuy: The biggest and toughest of the main group.
* BigNo: Binky busts out an epic one after a nightmare in "Binky Goes Nuts".
* TheBully: Moves away from this as the series progresses. HiddenDepths are eventually revealed and moves towards the GentleGiant.
* CouldSayItBut: Binky telling Buster how to liberate his confiscated toy car in "Buster the Lounge Lizard".
* EpisodeTitleCard: Binky blows a bubble gum bubble so big that he is CoveredInGunge when [[BubblegumPopping it pops]], and he gets stuck in the title card circle.
* FriendToAllChildren: While Binky is still a child himself, he befriends D.W. in S3's "The Chips are Down" and her friend Emily in S13's "The Good, the Bad, and the Binky".
* JerkWithAHeartOfGold: Seems to vary from sensitive soul who acts tough to genuinely stupid depending on the writer.
* [[spoiler:NamedAfterSomebodyFamous: His great-grandfather, Shelley Barnes.]]
* LethalChef: We find out Binky is this when he tries to make dessert for Christmas dinner at a soup kitchen. His attempts include pecan pie with shells and banana bread with peels.
* MyBelovedSmother: His mom is a mild-to-moderate version of this.
* [[spoiler: OnlyKnownByTheirNickname: S15's "What's in a Name" reveals that Binky is indeed not his real name. It is, in fact, Shelley, named after his great grandfather. Not only do his parents not call him this, even Binky ''himself'', didn't know.]]
* RealMenWearPink: Sleeps with a night light and takes ballet classes. Seems the longer the series continues, the less he tries to hide it. Heck, his shirt is even sort of pinkish-orange!
* UnmanlySecret: [[ZigzaggedTrope Zigzagged]] like crazy. When his character first starts developing unmanly interests, he tries to hide them, but then gets found out anyway. Though some people try to make a big deal of it at first, his perceived fierceness and reputation as a bully allows him to quell any teasing or bullying simply by growls, posturing and death glares. In later seasons, he still sometimes tries to hide it, but just as often is open about it. In Season 15's "I Wanna Hold Your Hand," he doesn't care one bit that his friends in the Tough Customers gang know that he's going to be performing in a clarinet solo, but is terribly afraid that one of them might find out that he still sometimes holds his mother's hand. When they do find out anyway, they chew him out... for not having a juicier, more embarrassing secret!
* WeWantOurJerkBack: Happens to Binky occasionally.
* WhyDidItHaveToBeSnakes: A focal point in S2's "Night Fright", as Binky can be get really scared in the dark.

!!'''Sue Ellen Armstrong'''

Arriving in the show in 3rd grade, she and her family are cats.

* ActionGirl: Shown to the skilled in martial arts, particularly Tae-Kwon-Do.
* CarnivoreConfusion: Sue Ellen is a cat. Ratburn is a rat. But they seem to get along fine.
** There's some sort of humor in the cat character being the vegetarian.
* CatsAreMean: Averted, as she is one of kindest in Arthur's group of friends.
* GranolaGirl: She becomes one in S8's "Sue Ellen Chickens Out".
** "Sue Ellen Vegges Out" gives her another level of this, when she decides to become a vegetarian after befriending a pig at a farm she visited. [[note]] Not unlike another [[WesternAnimation/TheSimpsons girl her age]] [[/note]]
* GreenEyes
* OnlyChildSyndrome: Main plot point in S2's "Sue Ellen's Little Sister". Come to the point where she spends time with D.W. however...
* ShipTease: S2's "Sue Ellen's Lost Diary" hints that Sue Ellen may have a crush on Arthur, following a debacle with her diary. This is a throwback to the book "Arthur's Valentine" where Arthur has a crush on the new student (Sue Ellen).[[note]] It's also worth noting that [[WordOfGod Marc Brown]] has said she was based on his "girlfriend" when he was younger. [[/note]]
* SixthRanger: Not always in the main group, but important whenever she is.
* TomboyAndGirlyGirl: Plays the tomboy to Fern's girly girl on occasion.

!!'''Fern Walters'''

Originally a background character, she and her family are dogs.

* AmateurSleuth: Fern, like Buster, has this as one of her trademarks. In sharp contrast to Buster though, Fern prefers classic novelized detectives like Sherlock Holmes, Literature/HerculePoirot and Literature/MissMarple, sometimes imitating any of them when she's on a case.
* AscendedExtra: Until S1's "I'm a Poet", she was a relative LivingProp. Lampshaded by Francine once Fern is finally driven to speak after a pushed BerserkButton courtesy of Binky.
-->'''Francine''': That's the most she's said all year!
* BewareTheNiceOnes: Francine and the Brain find out first hand in S2's "Draw!" and S12's "War of the Worms" respectively.
* {{Cloudcuckoolander}}: Not to Buster's extent, but still pretty out there.
* EpisodeTitleCard: A shot, taken from S10's "Fern and Persimony Glitchet", that shows her writing. The difference between the other, louder title cards is symbolic of her quiet nature.
* GreenEyes
* JitterCam: The intro to "Fern's SlumberParty". This does not help Fern at all.
* LetsSeeYOUDoBetter: Fern dares her classmates to put up or shut up when they insult her hobby.
* {{Nerd}}: She is a Mystery Novel {{Fangirl}}, being shown in S2's "Fern's Slumber Party" playing with a Franchise/SherlockHolmes action figure. S11's "Phony Fern" even has her (and George) role-playing as Hercule Poirot.
* NightmareFetishist: Along with mysteries, Fern is ''very'' fond of reading and telling scary stories.
** She's also known to enact scary pranks on people, or imagine terrible things happening to people while she smiles about it.
* ShrinkingViolet: As the show progresses, she becomes more out-going and socializes more, though she still retains a bit of shyness.
* SixthRanger: Not a part of the main group, but still an occasional friend.
* TomboyAndGirlyGirl: Plays the girly girl to Sue Ellen's tomboy on occasion.
* UnaccustomedAsIAmToPublicSpeaking: Her mom makes her throw a slumber party to improve her confidence. When it works, Fern's mom [[BreakingTheFourthWall gloats a little to the audience]].

!!'''Prunella Deegan'''

One of the few 4th graders in the show, she and her family are either poodles or rats ([[FlipFlopOfGod official sources disagree]]).

* AlphaBitch: During the earlier seasons. She mellows out a bit once ''Henry Skreever'' and Marina Datillo are introduced to the show in S6's "Prunella's Special Edition".
* BigNo: She screams it in the opening of S6's "Prunella's Special Edition", when she discovers her book that she found is blank.
** Prunella screams it again in "Prunella Packs It In", when she dreams that she is in college run by the clown.
** She screams once more in "Prunella in the Haunted Locker", when she dreams she was attacked by her locker.
* EpisodeTitleCard: [[LargeHam I PREDICT THAT YOU WILL SHORTLY SEE...]] (episode title read out loud), taken straight from S4's "To Beat or Not to Beat".
* {{Nerd}}: Earlier seasons would show that Prunella and her sister Rubella were obsessed with paranormal phenomena. Her ''massive'' love for ''Henry Skreever'' would later become one of her signature character traits.
* PhonyPsychic: Just like her big sister. Oddly, she still believes her sister even though she's using the same tricks.
* SixthRanger: She's a grade higher than most of the rest of the cast, so she only hangs out with them on occasion.
* YetAnotherChristmasCarol: She goes through one in S4's "Prunella Gets it Twice". Lampshaded when the "Ghost of Presents Past" interweaves Tiny Tim into the story.

!!'''Marina Datillo'''

Prunella's friend, also a fourth-grader, who presumably goes to school at Mighty Mountain. Prunella met her in "Prunella's Special Edition" and she's been a recurring character ever since.

* AcademicAthlete: Marina is a bookworm who's also great at gymnastics and yoga. In a brief scene, she's shown playing soccer at school.
* InspirationallyDisadvantaged: Averted. Marina is blind, but does not like people to make a big deal of it. She's also received a massive amount of CharacterDevelopment that's unrelated to her disability, which is somewhat unusual for a kids' show.
* {{Nerd}}: She and Prunella share a deep love of ''Henry Skreever'' novels, and both enjoy paranormal phenomena.
* SatelliteCharacter: She is defined entirely by her relationship with Prunella.

!!'''Lydia Fox'''

An eponymous fox and friend of the third/fourth grade cast who was introduced in later seasons.

* AcademicAthlete: We first encounter Lydia as a new friend of Brain; they met because an injury relegated him to a wheelchair during basketball season. Through this, we find out Lydia is a great basketball player, but is also highly intelligent and plays a mean game of chess. Additionally, she's great at twirling batons.
* CharacterDevelopment: A variant. She originated as the winning character of a kids contest, where her submitted name was Lydia Fox. When the official episode was made, she was never given a last name in dialogue. However, she got the full name Lydia Gordon[[note]]The last name of the kid who won the contest[[/note]] in the episode's credits. When she returned a few years later, the name Lydia Fox was canonized through in-episode dialogue.
* InspirationallyDisadvantaged: Averted. She uses a wheelchair, but it's not her only characteristic, and she's quite opposed to being given sympathy based on the wheelchair alone.
* TomboyAndGirlyGirl: Plays the tomboy to Muffy's girly girl in "Little Miss Meanie" from Season 18.

!!'''George Lundgren'''

Originally a minor character in the background, he is a moose; a rare sight in the show.
* TheAnnouncer: Takes up this hobby in "Baseball Blues".
* AscendedExtra: Though George existed since the beginning of the show, it was quite a long time before he was made into a full-fledged character, in S3's "Arthur's Dummy Disaster". Since then there have been more George-centric episodes.
* BigNo: Three instances:
** S8's Desk Wars, when his bubble-gum stegosaurus model is destroyed.
** S9's George Blows His Top, when Arthur asks him if George can tell him the time. He replies, "NO!! What is it with you people? GET YOUR OWN WATCH!!"
** S14's "Follow the Bouncing Ball", where his painstakingly arranged dominoes are knocked over by Francine.
* ButtMonkey: He is often the subject of Binky's bullying in the earlier seasons prior to his characterization. Once he becomes more important, he still frequently gets forgotten or ignored by his friends.
* ForgettableCharacter: Initially ''nobody'' could remember him. It's gotten better recently, but still occasionally comes up.
* LIsForDyslexia: Although the original portrayal is closer to AttentionDeficitOohShiny
* LongSpeechTeaTime: George gets Carl going on a monologue about trains. Since he can't get him to stop, it turns into the framing device for the story of how they met.
* MrImagination
* MysteriousProtector: This is George's entire relationship with his classmates, until they get to know him.
* {{Nerd}}: George is incredibly awkward around other people (in part because of his horns), and spends less time talking to living people than he does to his ventriloquist's dummy, Wally, ''which he made himself''.
* NeverLiveItDown: Giving Wally to D.W. Something that "Wally" has never let him forget.
* OnlySaneMan: On occasion; a notable example is "Do You Speak George?" when everyone insists on speaking only their own made up languages.
* SixthRanger: The main group frequently forget he even exists, so he only tags along on occasions.
* TruthInTelevision: Students with disabilities can submit exams and assignments in an alternate format, if they have documented their disability in advance.
* Ventriloquism: With Wally...
** ConsultingMisterPuppet...Who is regularly poached for advice.

!!'''Jenna Morgan'''

Another former background character in Arthur's class, she is a cat, entirely different from Sue Ellen though.

* TheAce: It is mentioned that Jenna is also good at sports, mostly at the ones Francine is not good at.
* AscendedExtra: Like George, it was quite a while before she became a character with a personality. Despite having only one episode with her as the main focus in the show's 15 seasons (S7's "Jenna's Bedtime Blues"), she is maintained as a prominent secondary character.
* InformedAbility: In S6's "The Good Sport" we're told that Jenna excels in a number of sports that it's hard to imagine her doing.
** This seems like a one-off joke at first, but later episodes actually show her playing those sports.
* MauveShirt: She has gotten a few spotlight episodes, but much less than the rest of the cast, and still generally remains underdeveloped.
* OutOfFocus: Jenna has only spoken once since season 9.
* [[WhyDidItHaveToBeSnakes Why Did It Have To Be Pull-Ups]]: Jenna's reluctance to put on her pull-ups as shown in her only focus episode, S7's "Jenna's Bedtime Blues".

!!'''Ladonna Compson'''

The Compsons are a family of rabbits with tan fur. They moved from Louisiana to Elwood City in the Season 16 premiere, "Based on a True Story". Ladonna is the third of four siblings. She has a penchant for oral storytelling, similar to Fern's love of poetry, or Sue Ellen's love for her journal.

* UsefulNotes/AmericanAccents: Southern.
* BigEater: So much so that her father calls her a "garbage disposal with legs".
* CoolBigSis: She has her moments, particularly during "Adventures in Budylon."
* GenkiGirl: Is quite the chatterbox and can be rather chipper at the right times.
** Especially when snowy season comes around, as seen in "Waiting for Snow"; Ladonna [[{{Squee}} squeeing]] in excitement becomes a RunningGag in the episode.
* StockYuck: She can't stand beets; just ''looking'' at beets upsets her stomach.
* TrademarkFavoriteFood: Cake, [[ King cake]] in particular.

!!The Tough Customers
->''"We're not bullies. We're kids who have a hard time expressing our emotions in a constructive manner." - Rattles''

The Tough Customers are a gang of bullies at Lakewood Elementary School, founded by Binky, who is the one member who is not in the fourth grade. In "Arthur's Big Hit", Binky decides to get rid of the club, but in later episodes the club is still there. They hang out on the jungle gym (aka: The Tower of Pain), and also have an entire lunch table reserved for themselves. In early episodes, especially Season One and Two, they were portrayed as malevolent malcontents, but this lessened as time went on. Initially, there were many members, including Binky, Rattles, Molly, but the core three are the only of the original club to remain: none of the others are seen very frequently after Season Four. Later, Molly, Rattles, and Binky are joined by Slink, who was previously just a one-shot character from an earlier episode. From then onward, those four are consistently portrayed as the entirety of the group.

* AerithAndBob: Molly, ''Rattles'', and '''''Slink'''''?
* AffectionateNickname / InSeriesNickname: It's subtle, but Rattles often refers to Molly by "Moll" rather than her actual name.
** Both of them refer to Binky as "Binks" on several occasions.
* BlueAndOrangeMorality: Due to their extreme displays HypocriticalHumor.
** In one episode, Arthur proclaims that he's thief to gain acceptance to their group, and they openly welcome him and congratulate him on his "art." Then when it's revealed he wasn't honest, Binky and Rattles berate him for lying.
* CharacterTics: Frequently and consistently seen with their rollerblades and skateboards.
** RollerbladeGood
* CharacterizationMarchesOn: They become less obvious bullies and just kids who can sometimes be thoughtless and mean.
** [[{{Jerkass}} Jerkasses]] -> [[JerkWithAHeartOfGold Jerks With Hearts Of Gold]] / [[HiddenHeartOfGold Hidden Hearts Of Gold]] / HiddenDepths
*** At least for Molly, Rattles, and Binky.
* {{Delinquents}}: As close as they could get on ''Arthur'', anyway.
** GangOfBullies
*** KidsAreCruel
* DependingOnTheWriter: Whether they're actually legitimately malicious or just rougher and tougher than most of the other students.
* DiminishingVillainThreat:In early seasons, they're truly nasty and unkind to other students. By Season Eight, the worst they do is claim the jungle gym for themselves and bar everyone else from playing there, and occasionally throw water balloons at other students.
* [[EvenBadMenLoveTheirMamas Even Bullies Love Their Mamas]]: Holds true for Molly, Binky, and Rattles.
* EveryoneHasStandards: When they realized they might have unintentionally hurt Pal in "Arthur Cleans Up", they look notably dismayed and upset.
* GoKartingWithBowser: Binky hangs out with the other kids on a regular basis, and Molly and Rattles can be seen doing the same in "Don't Ask Muffy" and "Bugged".
** FriendlyEnemy
* LocalHangout: The jungle gym.
** Oddly enough, they can be frequently found at the library, as seen in "Sue Ellen's Lost Diary" and "Arthur Makes Waves".
* MetalHead: Molly, Rattles, Slink, and maybe Binky.
* NoNameGiven: A few of the Tough Customer "extras" have names, like the male cat named Kieper and the male bear named Billy, but others remain unnamed such as a male dog, a male rabbit, a female cat, and a female aardvark.
* PetTheDog: In "D.W., Dancing Queen", Molly and Rattles step up to help D.W. with her ballet performance when Binky twists his ankle and is unable to dance onstage with her.
* RealMenWearPink: Especially Binky and later Rattles, but all of them dance ballet at some point.
** Binky, Slink, Molly, and Rattles all take part in a barbershop routine for the Summer Serenade in "D.W. Beats All".
* SchoolBullyingIsHarmless: [[PlayingWithATrope Sometimes.]]
* {{Tomboy}}: All of the girls.
* TrueCompanions: In spite of their faults, they stick by one another and help each other out, as seen in Seasons Eight and Nine.
** For example, when it was discovered that Binky was allergic to peanuts, Molly acted as bodyguard and prevented students with said food from sitting near him in order to preserve his health.
* VillainsOutShopping: Rather hilariously, Molly and Rattles can be seen at the front of the crowd at the meeting for concerned citizens in "The Scare-Your-Pants-Off Club".
* YoungerThanTheyLook: They can all pass for high shoolers.

!!'''Molly [=MacDonald=]'''

A fourth grade rabbit and one of the Tough Customers. She has a younger brother named James, who is friends with D.W.

* ActionGirl: The only female Tough Customer to remain and the only main female skateboarder.
* [[AloofBigBrother Aloof Older Sister]]: Averted. One might think she would be this, but she is close with James.
* AlliterativeName
** MeaningfulName: Her first name means "bitter", which certainly suits her malicious personality in the early seasons.
*** The derivation of her surname is from the Gaelic "Mac Dhomhnuill", translating as "The son of Donald". It is said that the personal name "Donald" translates as "world-rule". Molly is a bully who rules the playground.
* AscendedExtra: She started off as a generic bully girl in the Tough Customers, but later episodes gave her a MoralityPet in the form of her younger brother, a hidden creative side, a more relaxed personality (in comparison), and an overall more sympathetic presentation.
** CharacterDevelopment
* BerserkButton: If anyone tries to take the "Tower of Pain" from her, as seen in "The Law of the Jungle Gym".
* BlindingBangs: Her eyes have only been seen very briefly in a few episodes, such as "Agent of Change" and "Arthur, World's Greatest Gleeper".
** DelinquentHair
* CoolBoard: Her skateboard is black and wrapped with barbed wire around the middle.
* CoolBigSis: When James needs help, he goes to Molly.
* DefrostingIceQueen: Over the course of the series, though not especially evident. Most apparent in "Arthur Makes Waves".
** SugarAndIcePersonality
* DrillSergeantNasty: When coaching her younger brother for his swim meet.
* [[spoiler: ExpositoryHairstyleChange: After her StartOfDarkness.]]
* ForbiddenFriendship: With Arthur, prominently in one episode, though they keep it a secret due to their respective friends' disapproval. [[AesopAmnesia Though the writers seem to have forgotten about it,]] [[{{Shipping}} the shippers have not.]]
* FreudianExcuse: Averted. If anything, she seems to be from a wealthy, stable family. Not to say that stable, wealthy families don't encounter problems, and there could be issues beneath the surface, but the show doesn't appear to be taking this route for her.
** It turns out that [[spoiler: she was bullied herself when she was younger]].
* [[spoiler: HeelRealization]]: "The Last Tough Customer" is this for her.
* HiddenDepths: She cares a great amount for her brother and mom, is interested by storytelling and animation techniques, and is concerned by the lack of independent female characters in media.
* ImpliedDeathThreat: We don't hear what she said to Muffy in "The Law of the Jungle Gym", but even the other Tough Customers thought she went too far.
* JustFriends: With all of the male Tough Customers, as well as Arthur.
* LeanAndMean: Perhaps it's just because she's older and taller, but she's noticeably thinner than the main cast. This is especially apparent when she's standing next to the male Tough Customers, who are more stocky and muscular than her.
* MoralityPet: Her younger brother James is one for her, and [[spoiler: she decides to change her ways when she sees him repeating her mistakes]].
* MasculineGirlFeminineBoy: Compare her distinct lack of traditionally female interests and her rough-and-tough appearance to [[RealMenWearPink Binky's activities.]]
* NotSoAboveItAll: In "Arthur Makes Waves", she discovers she has a lot in common with Arthur after she stops trying to act cooler than him all the time.
* OffModel: At some points in early episodes, her BlindingBangs are shorter than usual, but her eyes don't show at all, giving the impression she has no eyes.
* OneOfTheBoys: To the extent of some ViewerGenderConfusion, as her demeanor and activities barely portray a hint of femininity.
** At one point, the male Tough Customers imagined her in a dress and were weirded out by the very idea.
** She took part in a barbershop quartet with Binky, Slink, and Rattles. All four wore traditional male barbershop costumes.
** In an ImagineSpot of 50's society, Arthur and his friends are shown wearing gendered clothing, letterman sweaters for the boys, poodle skirts for the girls, while the Tough Customers are depicted as greasers. Molly is wearing a dark leather jacket and jeans right alongside her male friends.
* PetTheDog: In "Law of the Jungle Gym", she can be seen several times being kind to a stray cat.
** She is often very kind to her younger brother, and much more patient with him than Arthur is with D.W.
** When other students come to her for advice, she tells them her best ideas and takes time to talk with them even though she would rather be skateboarding.
** "The Last Tough Customer" is one giant moment for her.
* PintSizedPowerhouse: A subtler example than most, but when she is arm-wrestling with Binky, she gives as good as she gets even though he's taller, heavier, and stronger than her.
* PositiveDiscrimination: She is depicted as the most intelligent, capable, and, besides Binky, sympathetic Tough Customer, and though she still remains tough, her bullying of other kids is less and less prominent in later seasons.
* UsefulNotes/{{Scotland}}: Her surname indicates Scottish heritage, and her (presumably paternal) uncle appears to have been born and raised there.
* SleevesAreForWimps: A rare female example. Molly is almost always seen wearing a denim jacket as a shirt with ragged edges from ripping off the sleeves.
* SiblingYinYang: Tough, confrontational Molly and her quiet, unassuming younger brother James.
* TheStoic: As a result of her BlindingBangs that hide her eyes, it's difficult to gauge her emotion when she isn't speaking.
** FieryRedhead: On other occasions, often when she gets lines.
*** RedheadedBully: Though her bullying habits are phased out as time goes on.
* SpellMyNameWithAnS: It's '''[=MacDonald=]''', not [="McDonald"=].
* StartOfDarkness: [[spoiler: Turns out she was a victim of bullying herself. Seeing James start to repeat the pattern prompts her HeelRealization.]]
* TertiarySexualCharacteristics: Mostly absent. The only physical indication of her gender is her bob, but that helps little when she's standing beside fellow Tough Customer Slink, who is male and has hair that's longer than hers.
* ThoseTwoBadGuys: While she often initially appeared in the background of some scenes along with other Tough Customers, Season Five onwards seems to be going forward with this route for her and Rattles.
** PlatonicLifePartners: As of Seasons Eight and Nine, Molly and Rattles are almost never seen apart, even for mundane activities such as walking the dog, or special occasions such as dancing ballet together.
* {{Tomboy}}: Out of all the girls on the show, Molly is probably the quintessential example.
** Binky had to convince her to dance ballet by telling her [[BlatantLies it was a new martial arts style.]]
* WomenAreDelicate: Averted. Undoubtedly the most aggressive female character on the show, even after her CharacterDevelopment.
* WomenAreWiser: From Season Eight onwards, most episodes featuring the Tough Customers portray her as the most level-headed and realistically-minded of the group.


A fourth grader who seems to alternate between being a cat, a dog, and a bear.[[note]]Since the nose is basically the same for all three, the ear shape is how to tell the difference. Rattles only took off his hat 4 times in 18 seasons, leaving plenty of time for the animators to forget minor details.[[/note]] Another one of the Tough Customers.

* UsefulNotes/AmericanAccents: {{Joisey}}. Northern New Jersey, to be exact.
* BewareOfViciousDog: He owns a mean, snarling dog, aptly named "Crusher."
* BookDumb: He has an extensive vocabulary, but has trouble spelling, as seen in "The Play's The Thing".
* CallingMeALogarithm: Inverted. He uses words he doesn't know to insult people, such as "bibliophile" and "philanthropist".
* CoolPeopleRebelAgainstAuthority: Played straight with him most of the time, but he is occasionally shown to have a certain degree of respect for those in charge.
-->Rattles: [[ItMakesSenseInContext (Protesting the idea that Mr. Ratburn would wear socks with holes in them)]] '''Mr. Ratburn wouldn't wear no sock full of holes! He's a very upstanding kind of guy.'''

-->Rattles: (Upset when someone puts trash in the recycling bin) Yo! It's paper only! Can't you read?!
* [[DarkIsEvil Dark Is Bad]]: A bully and one of the only two kids to have a recurring black article of clothing (in his case, a black jacket he constantly wears).
* ADayInTheLimelight: Season nineteen's "Whip, Mix, Blend."
* HypocriticalHumor: Yells at a guy for tossing regular trash into a paper-only recycling bin, minutes before intimidating some random children into giving their ice cream to him and Molly.
* {{Jerkass}}: Probably the most consistently antagonistic of the Tough Customers.
** HiddenHeartOfGold: He's still an okay guy deep down.
* NamesToRunAwayFromReallyFast: If his name refers to "Rattles" as in "Rattlesnake," he fits this. If it's the other kind of rattle, then not at all.
* NiceHat: He is almost never seen without his red baseball cap, always worn backwards.
* ThoseTwoBadGuys: While he often initially appeared in the background of some scenes along with other Tough Customers, Season Five onwards seems to be going forward with this route for him and Molly.
** PlatonicLifePartners: As of Seasons Eight and Nine, Molly and Rattles are almost never seen apart, even for mundane activities such as walking the dog, or special occasions, such as dancing ballet together.
* RealMenWearPink: His interests include sewing and knitting.
* RecurringExtra: He can often be seen in background scenes, more so than any of the other Tough Customers.
* SophisticatedAsHell: He often makes quite eloquent and mature remarks, but they end up sounding a bit ridiculous due to his exaggerated {{Joisey}} accent that makes his voice seem a bit thuggish.
* StockForeignName: Is implicitly of Italian descent.
* ThatLiarLies: In "Arthur: World's Greatest Gleeper". After he learns that Arthur lied about being able to gleep, he responds with a tirade that ends with "lying lie face".
* WhoNamesTheirKidDude: Seriously, ''Rattles''?


A fourth grade rabbit with a tanner complexion than Molly, and another Tough Customer.

* AscendedExtra: Initially a single-episode bully character from "Buster and the Daredevils", but is a recurring member of the Tough Customers by Season Six.
* BlindingBangs
** TheFaceless: Due to his hair. His bangs are even longer than Molly's, cover roughly half his face, and his eyes have only been seen once.
** DelinquentHair
*** WildHair: The only elementary school boy to have longer hair.
* [[DarkIsEvil Dark Is Bad]]: A bully and one of the only two kids to have a recurring black article of clothing (in his case, a black shirt with a red lightning bolt on the front).
* MeaningfulName: His moniker suggests that he may not be of the best repute. He isn't.
* SeriesContinuityError: When Slink was first introduced, he attended Mighty Mountain. He later appears at Lakewood Elementary with no explanation offered.
* WhoNamesTheirKidDude His name really takes the cake for this.

[[folder:Younger cast]]

!!'''Dora Winifred "D.W." Read'''

Sister of Arthur, and often the main character of episodes focusing on the younger cast.

* AllGirlsLikePonies: D.W. adores them. Her favorite idea for a holiday is Pony Day. Oh, and she loves unicorns too.
* AnnoyingYoungerSibling: To annoyingly frustrating degrees.
* BerserkButton: Teasing her about her full name, anything involving her snowball, or saying that Unicorns and other fantasy creatures are not real.
* BrattyHalfPint
* ChekhovsGunman: After an entire episode of [[JustTryingToHelp getting in the way]], D.W. saves her aunt Lucy's wedding in "D.W. Thinks Big".
* CompanionCube: Her snowball.
* ChromaticArrangement: In one episode, The Tibble twins do this to her clothes.
* DoesNotLikeSpam: [[PunctuatedForEmphasis "I! HATE! SPINACH!!!"]] Cue FullNameUltimatum.
** She got over it, though.
* [[EmbarrassingFirstName Embarrassing First]] ''And'' [[EmbarrassingMiddleName Middle Name]]
* FullNameUltimatum: Heard often due to the amount of trouble she gets in.
* GirlsLoveStuffedAnimals: She has a number of stuffed animals and sometimes carries them around, though this seems to show up more often in the books.
* GoToYourRoom: A frequent punishment of hers. Usually the worst she gets.
* HereWeGoAgain: The final scene in "D.W. Flips" has her begging for horseback riding lessons, after she narrowly avoided both quitting and breaking her neck in gymnastics.
** She caught Arthur's Chicken Pox.
* IMeantToDoThat: D.W. tries to do a cartwheel, and lands on her back partway through.
--> '''D.W.:''' I was doing a half - sault.
* IdioticPartnerConfession: Usually something like, "Wow, Arthur. This person isn't as scary as you say."
* InformedDeformity: S10's "[[OperationBlank Operation, D.W.!]]" has her with hearing problems. First she doesn't hear her teacher call her and later she turns the volume up on the television way more than it should be. It's determined that she needs an operation to remove fluid in her ears. However, throughout the rest of the episode, everyone talks to her normally and she hears everything just fine.
* InstantExpert: Usually at things that Arthur failed at.
* JerkAss: NO KIDDING. She's such a big jerk that she even got punched by Arthur in one episode, which she deserved.
* JerkWithAHeartOfGold: She's rude, bossy and is a right pain in the backside to Arthur, but a couple of times it is shown that she actually loves and cares about her brother deep down.
* KarmaHoudini: She's gotten away with her mischief many times.
* KickTheDog: "MOOOOOOM! Arthur broke a window!"
* LittleMissSnarker: Usually towards Arthur.
* OnlyKnownByTheirNickname: Nobody calls D.W. "Dora" or "Dora Winifred" unless it's her parents issuing a Full Name Ultimatum or they want to deal with a major tantrum. In S2's "D.W. Goes to Washington," Mr. Read actually didn't seem to remember her full name.
-->'''Mr. Read''': Her name is D.W.
-->'''Secret Service member''': That's it? Initials? You didn't give the kid a full name?
* PickyEater: D.W. has a long list of foods which she does not like, most of which are StockYuck vegetables. However, she did learn to like spinach after [[spoiler: being served a restaurant dish in which it was the secret ingredient.]] The teaser for "Kung Fool" also shows that she unexpectedly loved a very green, very foreign dish her dad made, so we can safely assume she's ditched at least some pickiness.
* RealTime: In "D.W. Gets Lost," Ed Crosswire asks for five minutes of Jane Read's time. This is how long she and D.W. are separated.
* SecurityBlanket: She has one called "blankie" which was the focus of both the book and television story "D.W.'s Lost Blankie." One of the show's title cards depicts her wearing it as a superhero cape.
* TagalongKid: Whenever she hangs out with Arthur's group
* TookALevelInJerkass: DW becomes this in "DW's Very Bad Mood".
* UnwittingInstigatorOfDoom: In "My Club Rules," when Arthur and his friends are in the treehouse discussing ideas for their parade float, DW barges in, wanting to hang out with them. Arthur, desperate to get rid of her, lies and says it's a "meeting" of the "Parade Float Club." DW immediately says she wants to "join." They have DW undergo "initiation rituals," such as kicking a bowling ball (which she refuses to do) and drawing a funny picture of Mr. Ratburn. They're so distracted from talking about the float that they're actually focused on making it a real club. A little while later, Muffy makes some snobby comments about how improvements can be made to Arthur's treehouse so it looks like a real clubhouse, and how club dues should be paid in order to implement the improvements. This leads to a fight amongst Arthur and his friends, causing them to form their own separate "clubs." They make up a few days later, of course, but still. It could be argued that if DW wouldn't have barged in to begin with, the argument wouldn't have happened and they'd still be discussing float ideas.
* [[WhyDidItHaveToBeSnakes Why Did It Have To Be Octopodes?]]: Saw an octopus up close during a field trip to an aquarium. While recounting the trip to her family, however, [[BlatantLies she claimed to have punched it]].

!!'''Kate Read'''

Arthur's and [=DW=]'s younger sister.
* BabyTalk: Kate has appeared in episodes where she can speak with other babies and [[AnimalTalk non-anthro animals]].
* GrowingUpSucks: Recently she's been losing her ability to speak with pets, now that she's learning to talk and walk.

!!'''Timmy and Tommy Tibble'''

A pair of twin bear cub boys, they're often the other major characters in episode focusing on the younger cast.
* AccidentalArt: The Teaser for "A Portrait of the Artist as a Young Tibble".
* {{Alliterative Name}}s
* AnythingYouCanDoICanDoBetter: Sometimes with each other, but usually with D.W. Their web page spells it out.
* BondOneLiner: D.W. calls to check on things in "Arthur Babysits", while the Tibbles are playing cowboy.
--> '''Timmy''': Arthur can't come to the phone right now. He's all tied up.
* {{Bratty Half Pint}}s
* ColorCodedCharacters: Tommy wearing a red scarf, Timmy wearing a blue scarf.
* EpisodeTitleCard: The boys use fake squid tentacles to scare D.W. off.
* [[JerkWithAHeartOfGold Jerks With Hearts of Gold]]
* HairColorDissonance: According to official art (and the books) their fur is brown but within the cartoons they're a greyish color, sometimes with a tint of green.
* HighTurnoverRate: Their babysitters, before Arthur.
* IKnowYourTrueName: An "Iron Fist" approach will not work when babysitting the Tibbles. Tell them a story, however, and they're more likely to cooperate.
* LionsAndTigersAndHumansOhMy: In the original books, the Tibble Twins and their Grandma were drawn as humans. They have since been anthropomorphized for the television series and latter books.
* RaisedByGrandparents
* SiblingSenioritySquabble: In "Whistling in the Wind", Tommy is said to be two minutes older, and it's confirmed in "Two Minutes". However, to stop their fussing over it, their grandmother backpedals, saying that they were born at the same time.
* SiblingTeam
* {{Spoiled Brat}}s
* TokenHuman: Originally.
* TricksterTwinsth
* TwinBanter: It sometimes gets physical.
* UnnecessaryRoughness: They spend an episode basically imitating the PowerRangers, and D.W. ends up needing stitches. The boys do apologize, though.
* WholePlotReference: [[Theatre/MyFairLady "My Fair Tommy."]]


D.W.'s best friend and major character in D.W.-centric episodes. She is unique among the show's characters as she is part rabbit, and part ape.
* ADayInTheLimelight: "Emily Swallows a Horse".
* AdaptationDyeJob: Prior to season 6 she had shorter hair. In the books she had her current length but it was the same color as her fur.
* CallBack: Emily beats D.W. and James in a swim meet, in a nod to her initial antagonistic appearance.
* GenderEqualsBreed: Both Emily and her mother are rabbits, while Emily's father is an ape.
* GratuitousFrench
* SpoiledSweet: She's spoiled with tons of possessions, a private nanny, a tutor, and fancy food. Yet she's generally one of the nicest and most polite kids in preschool.
* TookALevelInKindness: Is mean to D.W. for almost all of her first appearance in "D.W. Flips".
* WiseBeyondTheirYears: Somewhat justified in that in addition to kindergarten, she's also homeschooled by a tutor.

!!'''Bud Tucker Compson'''

Ladonna's younger brother, and D.W.'s newest classmate. [[spoiler: The only kid in preschool who can actually cope with the Tibble Twins.]]
* DeathGlare

!!'''Mei-Lin Barnes'''

Binky's baby sister. A bear cub, she was adopted from China in season 11. She mostly appears in Kate-related episodes.
* HappilyAdopted
* MoralityPet: Mei-Lin's adoption has done wonders for Binky's CharacterDevelopment.


[[folder:Adult cast]]

!!'''David and Jane Read'''
The parents of Arthur, D.W., and Kate.
* HouseHusband: Both of the Read parents work from home. While David has his catering business, much of the money comes from Jane, who's an accountant.
* LethalChef: Played with. While Arthur initially thought this, it turns out David is actually an amazing cook. It's when he's experimenting in his cooking that the meals turn out a bit questionable. Either way, David is certainly not as bad a chef as Grandma Thora.
* SupremeChef: David runs a catering business and he can make amazing meals... as long as he isn't experimenting.

!!'''Oliver Frensky'''
The father of Francine and Catherine. Works as a garbage man.
* FunPersonified: He's always cracking jokes, coaching sports, or having fun with his daughters.
* NiceGuy: Easily one of the nicest characters on the show.
* WorkingClassPeopleAreMorons: Averted. Though he is a blue collar worker, Oliver is a pretty smart and nice guy, though his daughters (especially Catherine) thought he should get a more "respectable" job.

!!'''Nigel Ratburn'''

The third grade teacher of the Arthur gang, and the primary adult character featured in the show. He is a rat, obviously.
* AmbiguouslyGay: He is single, [[Series/{{Seinfeld}} thin and neat]]. With the exception of some earlier episodes, he speaks in a somewhat "sing-songy" way compared to other adult male characters. His hobby is performing [[AllGaysLoveTheatre puppet shows]], and he owns and maintains quite a collection of marionettes.
* ADayInTheLimelight: "The Return of the King"; "The Rat Who Came to Dinner"; "Get Smart".
* BreakingBadNewsGently: "Everyone sit down, please. Mrs. [=MacGrady=] is sick. She has cancer."
* CoolTeacher: His students don't like to admit it, but his a nice guy who, while strict, is very concerned about his student's well being.
* EveryoneWentToSchoolTogether: S1's "Arthur's Almost Boring Day" showcases Grandma Thora's old home movies, revealing that David Read, Mr. Ratburn, and Mr. Haney all attended the same high school at the same time.
** S15's "The Butler Did... What?" also reveals Bailey and Mr. Ratburn were in the same high school class.
* EvilCounterpart: The one time we get to meet his mentor from college, he's shown to be a far more sadistic, cold and cruel version of Ratburn. Mr. Ratburn likely designed his teaching style off of being as work-intensive as his while being far less harsh to his students.
* FacePalm: When Muffy attributes the creation of the Dewey Decimal System to Thomas Edison.
* FreudianExcuse: The one occasion we encounter his mentor, who taught him everything he knows, its clear that Mr. Ratburn had to constantly work hard throughout his life to please him. His love of giving out homework most likely stems from this.
* GeniusSweetTooth: S3's "Dad's Dessert Dilemma" reveals that he LOVES cake.
-->'''Mr. Ratburn''': I just wanted of the Spring reading list-OH! Are you having cake?!?
** Would carry over in S4's "The Rat who Came to Dinner".
-->'''D.W''': There was no cake Arthur. Mr. Rathead was very disappointed.
* HeterosexualLifePartners: With ''Arthur's dad'' of all people.
* HiddenDepths: Mr. Ratburn is often seen by the Arthur gang as a cruel teacher who has no life outside of making kids miserable. At the same time, he likes [[Franchise/ScoobyDoo Spooky Poo]], and he volunteers as a puppeteer for children's puppet shows. Oh and of course, he goes giddy over cake.
* IWasToldThereWouldBeCake: S3's "Dad's Dessert Dilemma".
* {{Keet}}: Similar to Buster he loves eating sweets and he's a little ''too'' enthusiastic about teaching his students about subjects.
* MisunderstoodLonerWithAHeartOfGold: He doesn't have much of a social life and is feared and hated by his students for giving out homework, but he's actually a very nice and friendly guy.
* NiceGuy: He pushes his students to be the best that they can be, and won't take any nonsense from them. Overall, he's a really good guy.
* NotSoFast: When and if he does let students off the hook, he'll call for a tougher assignment to make up for it.
* NotSoDifferent: With Buster. Both love eating and cartoons. Not to mention if the high school video is any indication, he was also just like Buster as a teenager. When shown this particular video, Ratburn blushes and starts whistling innocently.
* OhCrap: In "Cents-less", he and his class go without spending money for a weekend. Unfortunately, he forgets to buy food before announcing the assignment. He puts on a puppet show to barter for some food.
* OnlySaneEmployee: While he's strict, he's the only teacher at Lakewood Elementary School who actually teaches his students properly. The only other competent employees are the lunch lady and the janitor.
* ReasonableAuthorityFigure: Despite the kids complaining about Ratburn being a Sadist Teacher, he's always looking out for their best interest and is usually the one to call out one of the kids if they're being OOC like Arthur in "So Funny I forgot to laugh".
* SadistTeacher[=/=]SternTeacher: The kids complain about Ratburn being this. Also frequently subverted when they realize he's not that bad of a guy (just a little strict and a bit too obssessed with handing out assignments) and he's actually succeeding in teaching them things.
* SpeciesSurname: Played straight. Guess [[RodentsOfUnusualSize what animal]] he actually is!

!!'''Herbert/Francis Haney'''

Mild-mannered, well-to-do, absent-minded bear principal of Lakewood Elementary School. Often involved in episodes taking place at the school, though he is also involved in community work.

* ButtMonkey: The early seasons often had some form of bad luck or misfortune happening to him, usually in the form of things falling on him, from raw hamburgers, to baseballs, to a bucket of popcorn, to Binky Barnes.
* CloudCuckoolander: He's a pretty spacey guy.
* EveryoneWentToSchoolTogether: Attended the same school as Mr. Read and Mr. Ratburn. Even back then, as shown in the old videos in S1's "Arthur's Almost Boring Day", he had bad luck.

!!'''Edward Edsel "Ed" Crosswire'''

Used-car salesman who is Muffy's father and somehow independently wealthy.

* ADayInTheLimelight: Despite (and perhaps due to)hinging on the kind of lesson that never seems to stick for Muffy, with Ed elbowing his way in on Muffy's class project, "Muffy takes the Wheel" arguably has more to do with his character development than hers.
* GoodParents: While he spoils his daughter rotten, he clearly loves her deeply and is very worried about her happiness.
* HonestCorporateExecutive: He's always trying to find new ways to sell his products, but he never makes false promises.
* HonestJohnsDealership: Subverted. He's not into false advertising, but is very...aggressive when it comes to selling cars.
* MeaningfulName: An Edsel was a type of car made by Ford known as a commercial failure, but one of the meanings of the name itself is "rich."
** Also "Crosswire." As in hotwiring a car.
*** It can also mean "crossed wires", as in RichInDollarsPoorInSense. It fits for his whole family.
* NonIdleRich: He's a used-car salesman and clearly takes his job seriously, despite the pampered princess life he gives his daughter.
* NouveauRiche
* RepetitiveName
* SelfMadeMan