Nominally the main character of the books (though most of the books are more of an Ensemble Cast thing], and by far the one who changes and develops the most over the series. He starts out as a very young boy who rarely strays from his mother, but over the course of several books grows into an independent and self-assured troll. Sometimes timid and overly-emotional, but generally brave, friendly and polite to everyone he meets.
Character Development: As a result of growing up; the Moomintroll of the first book, The Moomins and the Great Flood, is an almost completely different character from the Moomintroll who appears in the eigth book, Moominpappa at Sea.
Cowardly Lion: He has traces of this; usually when nothing is happening and he's only imagining the dangers, he's timid and scared — but whenever actual danger appears he faces it head-on almost without thinking.
Nice Guy: Very much so; he's an emotional and sympathetic person who basically wants everyone to be happy and gets upset when they aren't. Little My thinks this is a weakness, telling him not to feel so sorry for everyone, but in Moominpappa at Sea it proves to be his greatest strength, as he's the only one who manages to befriend the icy Groke and thaw her out.
Out of Focus: Has a minor role in The Exploits of Moominpappa, is absent from five of the nine stories in Tales of Moominvalley, does not appear at all in Moominvalley in November and plays a fairly minor role in the last Moomin story, An Unwanted Guest.
Moomintroll's mother, and basically the surrogate mother of everyone in the series. Calm, nurturing and seldom cross or upset, she usually likes to let her "children" find their own way in life, but is always ready with a comforting word and a piece of candy or two if anyone should need her.
Iconic Item: She's never seen without her handbag, and at times it seems almost like a kind of Security Blanket for her, as she's visibly upset and distressed when she doesn't know where it is. When, in Moominpappa at Sea, she leaves the handbag behind without a word, this more than anything is what convinces Moomintroll that everything has changed and nothing is the same anymore.
Write Who You Know: One of few characters in the books based on a real person, namely Tove Jansson's mother.
Moominpappa at Sea is probably the book in which we get into her head the best, learning her fears and concerns and thoughts about everything. This is also the book where she pulls away from everyone else, withdraws into herself and escapes into her own dreams and artwork because she can't handle the hardships real life is throwing at her — and the others barely notice.
Curiously enough, the Deconstruction is most apparent and visible in the very last novel, Moominvalley in November, in which Moominmamma doesn't even appear. She is, however, constantly referred to by the other characters and appears in the dreams and stories of the orphan Toft, who doesn't have a mother and whose expectations and hopes about her gets more exaggerated and caricature-like during the course of the novel. Finally, he has to confront the fact that the ultimate Yamato Nadeshiko that's developed in his dreams is not a real person at all and deep down he doesn't want Moominmamma to be like that.
The patriarch of the Moomin family. Kind of blustery and self-important at times, and sometimes his restless and adventurous nature get the better of him, but he's a kind and loving father and husband. He's an excellent seaman.
Doorstop Baby: He was found in a newspaper basket outside an orphanage. The identity of his parents is never revealed.
Parents as People: The biggest example of this in the series, and the trope becomes more and more apparent in later books. He's a good father for the most part, but his fatal character flaw is his self-obsession and tendency to get carried away by his own restless nature, which lead him to do inconsiderate things like run away from his family to go exploring for months at a time, or uproot their lives by taking them with him without asking if they actually want to.
Small Name, Big Ego: Most notable in The Exploits of Moominpappa, which largely consist of his memoirs and contains a lot of self-glorification and ego stroking.
Walking the Earth: Did a lot of this in his youth, and occasionally gets the urge to do it again.
A tiny, but fiercely independent and often mischievous Mymble; she lives with the Moomins and is sort of their unofficially adopted daughter. She's impossible to frighten or upset and has a cheerfully morbid imagination, but can be a good friend when she wants to be. After first appearing in The Exploits of Moominpappa, she shows up in just about every book since, more or less taking over Sniff's role as Moomintroll's surrogate sibling.
Moomintroll's first friend, who for the first few books lives with the Moomins as a sort of surrogate son/brother. He's an over-emotional, self-interested Lovable Coward, and the only character in the books who desires money and wealth. In the comic strip he's always trying various get-rich-quick schemes, but few of them have any success.
Demoted to Extra: He's a major character in the first three books and a minor recurring character on the fourth, The Exploits of Moominpappa, which end with him being reunited with his long-lost parents. After this, he only makes sporadic appearances and is often left out of the books altogether.
The Bus Came Back in the story The Dangerous Journey, where the protagonist Susanna (along with a Hemulen, Sorry-Oo, Thingumy and Bob) encounters him in the strange surreal landscape and he joins them in their search for Moominvalley.
The Drag-Along: When out on adventures he tends to spend much of the time worrying about dangers, complaining about the current situation, or refusing to go along. Ironically, whenever things are calm and uneventful he often starts wishing for adventure — Moomintroll even Lampshades this on occasion, though Sniff actually has a reason: "I'm not a lion. I like small adventures!"
Running Gag: In The Dangerous Journey, his tail keeps getting accidentally burned whenever he's near fire. Upon which he'll immediately blame whoever he's next to at the moment.
Moomintroll's best friend and Little My's brother; he's a philosophical and solitary vagabond and musician who lives a nomadic lifestyle, smokes a pipe and values freedom above all else. He keeps as few worldy possessions as possible; the only two things he owns and loves are his old green hat and his harmonica.
Berserk Button: Don't ever put up regulation signs or tell him that something's forbidden. He'll either explode in anger and tear down the signs, or he'll go and do the forbidden thing anyway just because he's been told not to.
Moomintroll's girlfriend. She's not a Moomin herself, but a Snork — a being that's almost completely identical to a Moomin except with the ability to change colors according to her mood. Extremely vain and often rather silly, but with surprising Hidden Depths.
Doppelgänger: for Moomin in the comics. In other media they tend to be more easily distinguished.
The self-declared "villain" of Moominvalley; he's a troublemaker and rascal who's always up to dodgy and probably illegal things. He was introduced in the comic strip and doesn't appear in any of the novels — only in the last short story, An Unwanted Guest, does he appear, as a "secret friend" of Moominpappa.
Extreme Omnivore: He can and does eat everything, up to and including the Moomins' furniture.
Jerk Ass: He's probably the only recurring character in the franchise without any real redeeming qualities.
The biggest threat and scariest creature in Moominvalley; she's cold and unfeeling and creepy, and everything she touches freezes. If she stays in one spot for more than one hour, the ground dies and nothing can ever grow there again. She starts out portayed as just evil and terrifying, but later books, particularly Moominpappa at Sea shows her as a pitiful, lonely person who longs for warmth, light and companionship but is unable to get them because her very nature kills all these things.
An Ice Person: Seems to be brought on by her own inner coldness and depression. She's alone, cut off from everyone and everything, she cares about nobody and nobody cares about her. This manifests as a literal iciness; wherever she goes everything freezes.
Defrosting Ice Queen: Literally. In Moominpappa at Sea she slowly develops a sort-of friendship with Moomintroll, and at the end of the novel she no longer freezes the ground when she walks on it.
Hemulens feature in most of the books and are tall, grayish cousins of the Moomins. They tend to have obsessive personalities and base their entire lives around one hobby or interest, which they fanatically pursue, be it stamp-collecting, organizing of others, winter sports or etiquette. They have very poor imaginations and are bad at relating to others, which means a lot of people find them overbearing, abrasive and annoying. However, they are well-intentioned and usually have other redeeming qualities. The most central Hemulen is probably the plant-collecing one who appears in two books (Comet in Moominland and Finn Family Moomintroll) and usually makes it into the adaptations.
Control Freak: Almost all Hemulens are this to some degree, though you do occasionally meet one who isn't.
Wholesome Crossdresser: Male Hemulens tend to wear frilly dresses rather than trousers. Nobody really knows why; it's just one of their quirks.
A friend of the Moomin family and sort of a Distaff Counterpart to Snufkin; she shares his calm, patient and philosophical nature, as well as his view that it's not good to have too many worldly possessions, but she's less solitary and not as restless.
The Moomins' neighbor, a "proper lady" who finds the Moomins' bohemian lifestyle distasteful. She is an obsessive Neat Freak who has three children and is always conscious of what happens in "finer families."
Canon Foreigner / Canon Immigrant: She debuted in the comic strip and makes it to most adaptations. In the books there are three (possibly four) characters who are names "the Fillyjonk," who share certain character traits with her but don't seem to be the same character.
Heroic BSOD: The Fillyjonks in the books tend to be prone to these. Most notably in Moominvalley in November, where the Fillyjonk has a near-fatal accident while cleaning house and suffers a complete nervous breakdown which she spends the rest of the book recovering from.
A small, shy and melancholic dog who dreams big and impossible dreams. He appears in books, comics and spin-off materials, almost always in a different role, with different relations, and different impossible dreams, but his basic timid and melancholic personality always stays the same.
Dogs Are Dumb: Not in the regular, stereotypical "dumb dog" way, but he tends to berate himself for being an idiot when he realizes how impossible his dream was all along.
Dog Stereotype: Averted. He is a tiny dog, but has none of the stereotypical bravery or agression associated with tiny dogs.
Everything's Worse with Wolves: A victim of this trope in Moominland Midwinter, his major appearance in the books. He spends the entire book Howling to the Night, longing and dreaming about joining his "brothers," the free and wild wolves, but when he finally does meet a pack of wolves he discovers that they're not friendly and not interested in him as anything except a quick and easy meal.
A very depressed and rather paranoid character who thinks everyone is either making fun of her or laughing at her behind her back. In the comic strip (and several other incarnations) she is depicted as the Moomins' housekeeper, and occasionally the owner of Sorry-Oo. In her sole appearance in the novels, in Moominsummer Madness, she is basically just a random forest creature swept along on the adventure, who eventually becomes a star actress.
The Eeyore: The biggest example in the franchise; her basic mood is depression and paranoia.
Maid: Her role in almost all the incarnations except the novels — though she does appear to be the Moomins' housekeeper in the final Moomin story, An Unwanted Guest.
Thingumy and Bob
Two small, unseparable creatures who speak their own strange language (in the original Swedish, they add the suffix "-sla" to most of their words, while in the English translation they speak mainly in Spoonerisms) and who stay with the Moomins for a time. They're both female, even if their English names would imply otherwise.
Blue and Orange Morality: Like small children, they have their own (and rather self-centered) view of right and wrong, and don't seem to understand that the rest of the world doesn't share this view. They do, for example, see nothing wrong with stealing whatever they want.
Spoonerism: In the English translation, they communicate using these.
Write Who You Know: Unconfirmed by Word Of God, but they're pretty clearly based on Tove Jansson herself and her first girlfriend Vivica Bandler. Their original Swedish names, "Tofslan" and "Vifslan" makes it even clearer.
A small, timid girl who was frightened so often and so thoroughly by her mean aunt that she turned permanently invisible. Brought to the Moomin family by Too-Ticky, in the hope that they could make her regain her confidence so she could become visible again.
Character Development: Uniquely, her development has a visible indicator: The more confidence and development she gains, and the more she manages to free herself from her Shrinking Violet persona, the more of her becomes visible.
Invisibility: Presented here as something that happens to people who are too timid.
The protagonist of the story The Dangerous Journey and the sole actual, normal human character to appear in the franchise. She is a bespectacled little girl who wakes up one morning, bored and annoyed with the world at large, who is swept away on a strange and dangerous adventure when her spectacles are mysteriously swapped out for a pair of magical ones. When she puts them on, the world around her transforms into a nighmarish but wondrous place, in which she ends up going on a journey along with Sniff, the Hemulen, Sorry-Oo, Thingumy and Bob, in search of Moominvalley.
Be Careful What You Wish For: Declaring her hatred for and frustration with how boring everything is, she wishes everything was different and she could experience something dangerous. She gets both those wishes granted, and it's scary.
Break the Haughty: Starts out bad-tempered and angry at everything — and then when she puts on the magic spectacles her aggressions take on a life of their own and twist the world around, turning her cat into a horrible beast and the world into a nightmare, and her own reflection (as seen in a pond) into a slimy, creepy monster. When her anger vanishes she starts encountering friendlier creatures in the new strange world, and she even apologizes for having turned the world into such a gruesome place.
Kindhearted Cat Lover: She has a pet cat, and though in the beginning of the story she's annoyed with it like she's annoyed with everything else, she does love it very much and is overjoyed to be reunited with it at the end of the story.
Unfazed Everychild: Though it does seem that her adventure is largely shaped by her own subconscious, and the dangers and terrors she faces represent her own darker side.