"spread himself out so that he was just a kind of a layer..."
See in text (Chapter X)
Twain lessens the impact of this gruesome description for the reader by making it impossible and almost cartoonish in its violence. Indeed, much of the violence in the novel seems cartoonish, divorced as it is from a basic understanding of anatomy, medicine, and even the laws of physics. Jim's snakebite, for example, couldn't possibly have been cured by drinking whiskey, because its alcohol content wouldn't have cleansed the wound unless it was poured directly over it; and yet, we believe that it happens because it's told with such confidence.
"before he was cold..."
See in text (Chapter XVII)
Huck makes a point of saying that Emmeline was very talented and that he respects what she did, but we can see here that he also finds her pictures morbid and depressing and thinks that the extraordinary speed with which she composed her "tributes" is a little disturbing, if not off-putting. We'll see Huck wrestle with his feelings about her and the Grangerfords as we get deeper into the story, but for now Twain wants us to see this as just another example of his dark humor.
"Don't anybody know?..."
See in text (Chapter XVIII)
Twain uses this senseless feud to both tragic and comedic effect: it's absolutely absurd that these families would blithely go around killing each other for no reason, and it's tragic because now the younger is paying for something that the older generation hasn't even bothered to remember. Huck's confusion about this feud further aligns him with the reader, who is also skeptical of the feud's efficacy.
"song-birds just going it!..."
See in text (Chapter XIX)
Note the warm, light, and happy tone of this passage now that Huck and Jim have returned to the raft. Huck enjoyed his time with the Grangerfords, but it seems that the raft offers him a necessary familiar comfort that was missing at the Grangerfords—especially towards the end of Huck’s stay when the family’s feud results in extreme violence. Nature offers Huck an escape from society’s rules and regulations, but it also offers him a sense of security. Huck is impervious to the brutalities and injustices of society while he is in nature—or so he thinks.
"she doesn't bray like a jackass...."
See in text (Chapter XXI)
Here we see how the Duke really feels about the King: he's not just a terrible actor, but he's uncultured, rude, and, well, a donkey. Given his performance at the camp-meeting, however, and his impressive haul of over eighty dollars, this antagonism on the Duke's part may be a result of jealousy.