! The Seven Monsters

!! In general
* AdaptationalModesty: One, Three, Four and Five are depicted wearing clothes, when they went naked in the original book.
* AdaptationalNiceGuy: The seven monsters in the original book were remorseless troublemakers who enjoy terrorizing humans, while the animated series makes them nicer and more interested in befriending and playing with humans than they are in scaring them. Even when they do end up doing something wrong, it is rarely deliberate and they tend to apologize and make restitution for their actions at the first opportunity.
* GentleGiant: All of them are significantly bigger than humans in addition to being very friendly.
* RelatedInTheAdaptation: The cartoon establishes that they're siblings, when the original book gave no indication at all that the seven monsters were related.
* VagueAge: It's nigh-impossible to determine the monsters' ages. While they're giants who look and sound like adults, they are frequently shown to lack basic knowledge that their mother or another person has to educate them about, which is often a subject adults are unlikely to be ignorant of, plus "The Whole Tooth" revolves around Six losing a baby tooth when it is impossible for adults to have any baby teeth left. On the other hand, flashbacks to when they were younger clearly show them to be significantly smaller as young children, Three's personas frequently have his character demonstrate knowledge and skills that he'd realistically obtain through years of higher education and the alternate timeline shown in "It's a Wonder-Four Life" shows most of the monsters in lines of work where they'd have to at least graduate high school to be eligible for hiring (such as Six's counterpart being a dance instructor while Two and Seven's counterparts run their own stores). While their Mama does say in "Seven Monsters and a Baby" that it has been 40 years since she last had a chance to rest, she says nothing about where in that timeframe her children were born. The best guestimate is that they're "kids in monster years".

!! One
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/one_2.png]]
[[caption-width-right:250:One]]
-->'''Voiced by:''' Creator/JoanneVannicola
The eldest of the monsters, One is a tomboy who often tries to be responsible, but is usually undone by her bossiness. Although she is easily worked up and gets frustrated by her siblings' antics, she really does care about them.
----
* AccessoryWearingCartoonAnimal: For some reason, the show's tie-in books by Volo depict her as not wearing any clothes besides her hat.
* AllFlyersAreBirds: Sort of; she not only has wings but also birdlike talons for feet.
* FieryRedhead: One has red hair and can get easily tempered whenever her siblings get rude and do something bad.
* {{Flight}}: She's the only monster who can fly, considering she's the only one with wings.
* MadLibsCatchphrase: "You didn't just say [number higher than 7]", which leads into a song-and-dance routine by the monsters.
* NeatFreak: She brings up in "Nightmare on Chestnut Street" that her worst nightmare is dusting a long hallway only to turn around and see that it's instantly become filthy again.
* PinkMeansFeminine: Subverted. Her cap, long shirt, and shorts are all shades of pink, but she's a tomboyish [[PassionateSportsGirl sports girl]].
* TheStoolPigeon: Sometimes squeals on her siblings when they misbehave; most notably in the episode "I'm Telling".
* TeamMom: She tries to act like one when their mother isn't around, but she can't keep her rambunctious siblings under control at all, nor can she keep her patience with them.
* {{Tomboy}}: She loves playing all kinds of sports.
* TomboyAndGirlyGirl: The athletic tomboy to Six's girly girl.
* TwoGirlsToATeam: She and Six are the only two females among the seven monsters.
* WingedHumanoid: Has a pair of short wings on her back.

!! Two
[[quoteright:283:https://static.tvtropes.org/pmwiki/pub/images/two_8.png]]
[[caption-width-right:283:Two]]
-->'''Voiced by:''' Creator/ColinMochrie
The most helpful of the monsters, Two has a very prominent nose which he often sticks where it doesn't belong. Bit of a goody two shoes.
----
* AdaptationDyeJob: He has dark brown hair, when he was blond in Maurice Sendak's original book.
* ButtMonkey: Often meets with misfortune either from his siblings or through humorous circumstances.
* CursedWithAwesome: He goes through "The Nose Knows" believing that his big nose is more of a curse than a blessing until his nose leads him to find their missing pet Belinda.
* GagNose: Two often gets into really sticky situations involving his nose, like, for instance, he accidentally poked [[CheerfulChild Five]] in the episode "Good Morning!", his nose got crooked and said a really bad word in "[[ExactlyWhatItSaysOnTheTin The Bad Word]]", and he sneezed a whole lot of times, like in the episode "It's a Wonder-Four Life".
* NiceGuy: He is one of the nicest, if not, most nicest characters on the show.
* TheNoseKnows: The episode "The Nose Knows" is the trope namer. His nose can come in handy a lot of different ways, like for example, getting a cat off a tree, and later, getting Belinda out of a tree.
* SitcomCharacterArchetypes: The Square. In contrast to his wackier siblings, he's usually the most down-to-earth.
* StraightMan: Shares this role with One as a more sensible character reacting to the antics of his zanier siblings.
* StrongFamilyResemblance: Their mother often says that he reminds her a lot of his father.

!! Three
[[quoteright:266:https://static.tvtropes.org/pmwiki/pub/images/three_5.png]]
[[caption-width-right:266:Three]]
-->'''Voiced by:''' Creator/DwayneHill
The most dramatic monster who takes on a new role each episode. Although he is perhaps the weirdest monster, he also seems to have the most knowledge.
----
* AlasPoorYorick: His persona in "April Fools" and "A Pony Tale" is a William Shakespeare pastiche named William Three, both episodes appropriately featuring an homage to ''Theatre/{{Hamlet}}'' where Three holds Seven's head in a manner similar to Hamlet holding Yorick's skull.
* AttentionWhore: He ''loves'' being in the spotlight. He even takes on the role of baby in one episode to compete with the affection of a neighbor's newborn.
* BreakingTheFourthWall: He sometimes directly speaks to the audience, with some of these instances even having him serve as the episode's narrator.
* BunnyEarsLawyer: Most of the personas are rather quirky and eccentric individuals, but nonetheless prove themselves to be rather intelligent.
* {{Cloudcuckoolander}}: Just about every episode has him adopting a different persona for no reason.
* {{Cosplay}}: In most episodes, he wears a costume appropriate for the persona he's used for the episode.
* DramaQueen: Quite literally. He takes on a different character role almost every episode.
* GeniusDitz: In spite of his loopiness, he can be very insightful and observant at times and often gives informative lectures to his siblings about everyday topics.
* LargeHam: His disguises can be quite hammy sometimes.
* ManOfAThousandVoices: His actor gives him a distinct voice for every persona.
* MockCousteau: "My Favorite Crustacean" has him adopt the persona of Jacques Threesteau, who speaks in a French accent and tells his siblings facts about marine life.
* MrExposition: He's usually the one to explain a new concept to the others.
* NonActionGuy: Whenever the other monsters are on a team sport, he usually doesn’t participate, instead opting to be their referee, a sports announcer, or just off doing his own thing.
* TuxedoAndMartini: In the episodes "The Big Store" and "No Place Like Home", his persona is a secret agent with a Scottish brogue named Double-O-Three, a clear homage to Creator/SeanConnery's portrayal of Franchise/JamesBond.
* WhyDidItHaveToBeSnakes: He is really afraid of mice, according to the episode "The Adventures of Super Three".

!! Four
[[quoteright:251:https://static.tvtropes.org/pmwiki/pub/images/four_3.png]]
[[caption-width-right:251:Four]]
-->'''Voiced by:''' Creator/SeanCullen
Grumpy, selfish and rambunctious, Four has a troublesome and negative personality. Despite his flaws, though, he loves his siblings and usually does the right thing in the end. He is almost always seen with Five.
----
* AgentScully: He is by far the most skeptical of the monsters.
* {{Catchphrase}}: "Who are you supposed to be today, Three?"
* DeadpanSnarker: He fits this role both audibly and visually.
* GreenAndMean: He has green fur and, while not a completely rotten person, is shown to be the meanest of the seven monsters.
* HalfDressedCartoonAnimal: He doesn't wear pants.
* JerkWithAHeartOfGold: Despite his nasty temper, he is shown to love his siblings a lot. As is, a mild example is this episode "It's a Wonder-Four Life", where he gets annoyed by his siblings' antics to the degree that he wishes he were an only child, but regrets having his wish come true and is grateful to have them be his family again after he undoes his wish.
* MiddleChildSyndrome: As the middle child, he doesn't feel like he has things as good as his older and younger siblings.
* TheNapoleon: He is the shortest of his siblings, although he's still a giant.
* NoRespectGuy: His {{Jerkass}} tendencies don't earn him any respect from his siblings.
* SiblingRivalry:
** With Three, with whom he gets into a fair amount of arguments. He also frequently challenges Three's knowledge.
** With One, because he wants to be in charge and resents having not been born first.
* TokenEvilTeammate: He's not entirely a bad guy, but is noticeably the most self-centered, rude and grouchy of the monsters.
* {{Troll}}: In "Good Night", he disregards One's insistence that he not say "Don't let the bedbugs bite", knowing full well that the mention of bedbugs will upset Seven.
* VocalEvolution: His voice was originally deeper and gruffer in the first two episodes, "Good Morning" and "Good Night".

!! Five
[[quoteright:251:https://static.tvtropes.org/pmwiki/pub/images/five_2.png]]
[[caption-width-right:251:Five]]
-->'''Voiced by:''' Creator/SeanCullen
The most child-like of the monsters, Five follows Four like a lost puppy and seldom speaks, and when he does he speaks with a thick accent that requires Four to translate for him.
----
* AnimalLover: He is especially fond of animals.
* AcroFatic: The biggest monster but no less rambunctious than the others.
* BigEater: Throughout the whole series, he is shown to be eating large amounts of food.
* BigFun: He is one of the most fun monsters in the whole series.
* CheerfulChild: He is quite energetic a whole lot.
* ChildishOlderSibling: He acts the most immature of the monsters, even his younger siblings Six and Seven.
* ElmuhFuddSyndwome: When he does talk.
* ExtremeOmnivore: He sometimes eats stuff that isn't usually edible. "Seven Monsters and a Baby", for example, has him eat a treasure map and a bar of soap.
* GagNose: His nose makes a honking sound a whole lot. As is, a rich example would be in "The Mystery of the Missing Five", when Six accidentally steps on his nose, sounding more like a "Arrrrrrnk!".
* KiddieKid: He acts the most immature out of all his siblings, even Six and Seven who are younger than him.
* MoralityPet: He brings out Four's good side.
* MultipurposeTongue: His tongue is often used as an extra appendage when he has to reach for something his hands aren't close enough to get to.
* OverlyLongTongue: His tongue comes in handy, either to lick people or to pick up food.
* TheUnintelligible: Though it's a little more comprehensible, even in later episodes. Four translates for him.

!! Six
[[quoteright:235:https://static.tvtropes.org/pmwiki/pub/images/six_05.png]]
[[caption-width-right:235:Six]]
-->'''Voiced by:''' Creator/MicheleScarabelli
The resident ballerina, Six thinks she's the most beautiful of the monsters, and often worries about her appearance.
----
* {{Ballet}}: She goes to ballet class, and is [[LimitedWardrobe always seen wearing her tutu and carrying her ballet wand]].
* TheDitz: She isn't really stupid at all, but she occasionally has airhead moments, mostly by being oblivious to her surroundings.
* DramaQueen: She can be very melodramatic at times.
* TheFashionista: She's a bit obsessed when it comes to wardrobe.
* GirlsLoveStuffedAnimals: She ''has'' to be crazy about stuffed animals, considering her bed is ''full'' of them.
* GirlyGirl: She is considerably more traditionally feminine than her older sister One.
* GracefulLadiesLikePurple: She wears a purple tutu and is very in tune with her femininity.
* TheKlutz: Ironically, for the most graceful monster, she is.
* {{Pride}}: She's very vain.
* RunningGag: For someone so graceful, she's tripping over her own feet every other episode.
* SleepyHead: She needs her beauty sleep, after all, so it's common for her to be asleep at inappropriate times.
* TomboyAndGirlyGirl: The ballet-loving girly girl to One's tomboy.

!! Seven
[[quoteright:172:https://static.tvtropes.org/pmwiki/pub/images/seven_5.png]]
[[caption-width-right:172:Seven]]
-->'''Voiced by:''' Creator/SeanCullen
The youngest of the septuplets, Seven is the tallest but most timid and gentle of the monsters. He has a detachable head, which he is prone to losing.
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* BorrowedCatchphrase: "Doctor, Doctor" has him say "You didn't just say [number higher than 7]" instead of One, as One is the one who said a number higher than 7 (i.e., 10) that time.
* CraniumChase: He occasionally tries to chase after his detachable head after losing it, and is always PlayedForLaughs.
* KarloffKopy: His voice is very similar to Creator/BorisKarloff, which is rather appropriate given that his physical appearance is somewhat reminiscent of FrankensteinsMonster.
* TheKlutz: He can be very clumsy.
* LosingYourHead: He can remove his own head and live.
* LovableCoward: He's the most easily scared of the monsters, but is just as friendly and nice as the other six.
* NervousWreck: He is a frequent worrywart.
* PerkyGoth: He's got the voice and look of a classic movie monster, but is in reality very sweet.
* RequiredSecondaryPowers: His head screws on and rolls around a lot when detached but he appears immune to motion sickness.
* TheStoryteller: He is sometimes shown to have a knack for spinning yarns, with "Losing Sam" having him try to make Five feel better about the disappearance of his pet turtle Sam by conceiving an elaborate story about Sam winding up in a different land and "A Five-y Tale" having him make up a story about a hedgehog named Donovan who goes on a quest with a pair of lizards to rescue a princess. The latter episode also has it mentioned that he's almost as good at telling stories as the monsters' mother is.
* TrademarkFavoriteFood: He really likes to eat cheese.
* WhyDidItHaveToBeSnakes: He is very scared of bugs, to the extent that in "Good Night", telling him not to let the bedbugs bite backfires due to making him too frightened to go to sleep.

!Other Characters

!! Mama
[[quoteright:254:https://static.tvtropes.org/pmwiki/pub/images/7monsters_mom.png]]
[[caption-width-right:254:Mom]]
-->'''Voiced by:''' Creator/DebraMcGrath
The monsters' mother. A tiny woman who speaks in a heavy accent and usually provides her children with support and the episode's [[AnAesop Aesop]].
----
* CanonForeigner: She had no indication of existing in the original book and was created for the animated series.
* FunnyForeigner: She speaks broken English in a Slavic accent for no apparent reason other than her dialogue being funnier that way.
* [[GoodParents Good Parent]]: Let it not be said that she doesn't love all seven of her children.
* HammerSpace: She sometimes pulls stuff from her apron pockets that realistically would be way too big to fit.
* JerkassBall: She's usually a caring parent, but when she gets annoyed by her children making too much noise while Two is trying to come up with a song in "All's Quiet on the Monster Front", she kicks them out of the house while it's raining.
* TeamMom: Of course, she's the monsters' mother and the main voice of guidance.
* UnnamedParent: She is only called "Mama".

!! Belinda
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/belinda_5.png]]
[[caption-width-right:250:In her first appearance.]]
The monsters' pet cow, who they bring home from the grocery store in "Good Morning".
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* AllAnimalsAreDogs: In spite of being a cow, she sometimes behaves like a canine.
* CanonForeigner: She did not exist in the original book and was created for the animated series.
* TeamPet: She's the group's token domesticated animal.

!! Mary
[[quoteright:250:https://static.tvtropes.org/pmwiki/pub/images/mary_27.png]]
[[caption-width-right:250:In the ep "A Pony Tale"]]
-->'''Voiced by:''' Unknown
The monsters' next-door neighbor.
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* AudienceSurrogate: She is an average girl who adjusts to living next to a house full of monsters.
* CanonForeigner: Like with just about every character in the animated series besides the seven monsters themselves, she was created exclusively for the cartoon and didn't exist in the original book.
* NiceGirl: She's a pleasant girl who quickly befriends the seven monsters.
* TotallyRadical: She uses slang from the '60s such as "groovy" and "far out", though she isn't a NewAgeRetroHippie.