In Chapter 14, while Huck and Jim are floating down the river on their raft, Huck first begins to try to educate Jim about royalty. He says,
“I read considerable to Jim about kings and dukes and earls and such, and how gaudy they dressed, and how much style they put on, and called each other your majesty, and your grace, and your lordship, and so on, ’stead of mister; and Jim’s eyes bugged out, and he was interested.”
In addition to telling Jim about King “Sollermun” (Soloman) and the “Dolphin” (Dauphin) in Chapter 14, Huck also attempts to enlighten Jim about the behavior of the King and the Duke later in the novel. After the King and the Duke bilk a town out of $465.00 with their Nonesuch Show, the King and the Duke have to escape from their unhappy customers back to the raft. Jim calls the royals “rapscallions,” and Huck begins to explain to Jim that royalty are all rapscallions who “lie, steal, and decapitate” their subjects. Huck knows that the King and the Duke are frauds; however, he is afraid to completely go against them at this point because Huck is unsure if they know that Jim is a runaway slave. Huck attempts to “clue in” Jim about the King and the Duke without giving too much away about his suspicions of them being simply con artists.
Twain is poking fun at many aspects of royalty who “put on frills," are greedy, and are liars. All of these characteristics describe the King and the Duke as they pretend to be something they’re not for material gain. Twain also pokes fun at the governmental system of a monarchy that rules people with power and wealth.
I will assume that you are asking about the discussion between Huck and Jim in Chapter 14.
There, Twain pokes fun at a few aspects of royalty. First, he pokes fun at their greed. He talks about how they own everything and have everything they want. Then he mocks the fact that (in his mind) they are worthless. He talks about how they never do anything at all -- just sit around or go to their harem. Finally, he mocks their wastefulness. He talks about how they use their money dressing up in fancy ways and putting on airs.
In this conversation, Twain is showing good republican criticisms of monarchy -- he is poking fun at its wastefulness and its uselessness.
First of all, it is important to note that Twain is not describing the role of kings; Huck is. The child’s point of view makes what might otherwise be just plain repulsive about royalty darkly funny.
Through Huck’s descriptions in Chapter 14, Twain pokes fun at the shallowness and superficiality of royalty, noting “how much style they put on” and “how gaudy they dressed.”
He ridicules the indolence of royalty who “just set around” and the entitlement that allows them to “get a thousand dollars a month if they want it.”
But the unchecked power and immorality of royalty are the main targets of Twain’s jibes. Huck describes them as tyrants who whack off the heads of those they disagree with, “fuss with parlyment” for amusement, and otherwise, “hang round the harem.” Because “everything belongs to them,” they are exempt from all rules of morality, decency, and fairness. Their later interactions with the king and duke, underscore these unsavory aspects of royalty for Huck and Jim, and for the reader.