* AdaptationDisplacement: 90's anime in Scandinavia and Japan. Late 70's-80's series in the rest of Europe.
** It's not volatile, unlike 99% of the internet, but Moomin fans can't seem to decide which foreign dub of the series is best. English? Finnish? Polish? French?
** Whether the heavily Bowdlerized anime series is an acceptable adaptation at all. Especially older fans (i.e. the parents of the generation who saw the series in the 90's) seems to be more hostile towards it.
* EarWorm: The theme tune to the animated adaptation. ''They were the Moomins, ba-papa-da-ba-da-bada-ba-ba...''
* EnsembleDarkhorse: Almost everyone outside the main character. The first one that pops in mind is Snufkin, but Little My is almost as popular.
* FandomBerserkButton: Refer to the Moomins as "hippos" and find yourself instantly marked for death by the Finnish government.
* FanonDiscontinuity: Not very many people like the 1990s series' 3rd season, ''Bouken Nikki'', too much.
** For a Finnish franchise, the Moomins are extremely popular in Japan.
** The anime series was popular in Hawaii, airing on the local UPN affiliate.
** It's also popular in Poland (got a rerun in 2006) and in Israel (basically everyone who was born between the mid-[[TheEighties eighties]] to the early [[TheNineties nineties]] grew up watching it), but it was no doubt most popular in Finland, where it reruns regularly. Heck, you KNOW a series is popular in another country when they manage to dub EVERY SINGLE EPISODE and the BigDamnMovie on top of it!
* HeterosexualLifePartners: Snufkin and Moomin.
* HilariousInHindsight: In one episode, Snork Maiden (known as Floren in Japan) develops psychic powers and has visions of the future. About six years later, her seiyuu, Creator/MikaKanai, would go on to play [[Anime/AfterWarGundamX another such character.]]
* MemeticMutation: '''EVERYONE''' in Scandinavia and Poland is afraid of the Groke, no exceptions. The show was immensely popular, and everyone of the generation that watched the 90's animated series remembers that freaking thing. It was one of the only times in Scandinavia that a show was pulled off the air (for a time) because parents called and complained about it being too scary. That almost never happens there.
** [[http://syko.typepad.com/.a/6a010536bfff2d970c012875f7273a970c-pi Too-Ticky]] and the Groke. You wouldn't know they were female simply by looking at them.
** Not to mention Thingumy and Bob. You might presume they're female like their real life counterparts but the English names are rather confusing, especially "Bob". And the original names, Tofslan & Vifslan, give even less of a hint of their genders. The original Swedish novel never mentions their genders. But it does it so skilfully that you won't notice until you start wondering what their genders are.
** For the readers of the Finnish translation this goes UpToEleven. Unlike Swedish (and English) Finnish doesn't distinguish gender grammatically, not even in pronouns. Thus there's no he/she distinction. One can read all the books and all the comics and watch all the adaptations in Finnish and never find out the genders of the more ambiguous characters. Hence the confusion of many Finns when they find out the Groke was female all along (not helped by the voice given to her in the Finnish dub of the animated series). Thingumy and Bob are similarly difficult to figure out. Too-Ticky is slightly easier since her name sounds a lot like her real life counterpart's Tuulikki, which is a Finnish woman's name. (And even then people can be confused. While the -kki ending is more common in feminine names, it's by no means a strict rule.)
* WhatDoYouMeanItsForKids: Uniquely, the Moomins fit this trope and WhatDoYouMeanItsNotForKids. The later books in the series ''aren't'' really children's books (something which Tove Jansson herself acknowledged), touching on a lot of themes that kids won't understand. The newspaper comic, while less dark, contains a lot of satire directed primarily at adults: The Moomins' bohemian lifestyle is often mocked, with the characters played for fools in a lot of subtle ways, but other, more "normal" lifestyles are frequently held up for examination and found to be even more foolish. At the same time, earlier books and works which ''are'' primarily directed at children, contain some pretty dark undertones and subtle adult humor. The '90s animated series and its spin-offs are more clearly aimed at children (though even there the undertones aren't completely gone AND The Groke is still there), which is the main reason why so many older Moomin fans don't like it.
* WhatDoYouMeanItsNotDidactic: There's a book that uses the characters to illustrate concepts from existentialist philosophy. It works surprisingly well.
** The Groke especially gets this treatment in the last books.
** Sniff, especially in the books. Completely averted in the comic strip, where he's more a KarmaHoudini -- and so, in the animated series, which takes cues from both books and comic strip, he's a JerkassWoobie.
** Sorry-Oo was basically designed to be this.
** Ninny, the invisible girl who was abused by her aunt
** Fillyjonk's children. They are not allowed to have fun!