* AngstWhatAngst: Huck is very cavalier about his father's unavailability and [[AlcoholicParent drunkenness]], his [[MissingMom mother's apparent death]], and the fact that he's living on the streets--in fact, when people attempt to give him the maternal love they believe he needs, he only gets embarrassed.
* CompleteMonster: Injun Joe. Murders a man in cold blood and frames someone else for it [spoiler: almost successfully]. Plots a gruesome revenge -- facial mutilation and being left to die -- against the widow of a deceased judge who had him jailed and flogged for vagrancy.
* {{Sequelitis}}: Not for Literature/HuckleberryFinn, but the further sequels "Tom Sawyer Abroad" and "Tom Sawyer, Detective." Yes, those really exist. And they were written by Mark Twain himself, too. He lost much of his wealth in bad investments and he needed to support his family.
* SignatureScene: Tom Sawyer tricking other kids into whitewashing a fence for him ([[CommonKnowledge although contrary to popular belief]], in the original Huckleberry Finn wasn't present; he was only introduced later).
* UnintentionallySympathetic: Mr. Dobbins for some adult readers. When young he had very much wanted to become a doctor but was unable to continue his studies for financial reasons. Hence he ended up a country school teacher (which was not considered a prestigious job for men in the nineteenth century). He still enjoys reading his anatomy text, but then one of his students has the nerve to go through his desk and damage his book.
** However, it is also highly implied that during school hours he reads the part of the book with pictures of naked women. [[{{Squick}} In front of little children.]]
** Adult readers also tend to find Aunt Polly much more sympathetic; for all her faults, she is doing her best to raise her nephew and two other children on her own. Further, she's subjected to the worst AdultFear -- [[spoiler: the loss of a child]] -- not once, but twice, in the course of the book; her emotional torment is all too clear, especially to readers who are parents themselves.
* ValuesDissonance: [[CorporalPunishment Beatings]], whether at school or at home, were quite common, and Huck even states that his back doesn't mind any more.
** Injun Joe has caused controversy too among modern readers. At least one animated adaptation even went as far as to rename its depiction of the character as "Tattoo Joe".

!!The Adventures of Tom Sawyer: The Musical
* [[CrowningMusicOfAwesome Crowning Music Of Heartwarming]]: "This Time Tomorrow" - a little song by Aunt Polly as she watches her nephew, musing over the growing process of children and assuring Tom that she will always love him.

!!The {{Licensed Game}}s
* TheProblemWithLicensedGames: The SETA game is just another ''VideoGame/SuperMarioBros'' clone and has to do with little to none of the novel, except the characters.

!!The Anime/WorldMasterpieceTheater version
* EarWorm: [[https://www.youtube.com/watch?v=S8Po5z1lxOU The ending, "Boku no Mississippi"]]