* The pretentious and hypocritical: Twain often satirizes the upper class and their perceived arrogance, hypocrisy, and obsession with appearances. This is evident in characters like Aunt Sally and Uncle Silas in *The Adventures of Tom Sawyer* or Colonel Sherburn in *Adventures of Huckleberry Finn*.
* Superstition and ignorance: Twain frequently mocks the superstitions and prejudices of his time, particularly those surrounding race, religion, and education. This is evident in characters like The Grangerfords and Shepherdsons in *Adventures of Huckleberry Finn*.
* Politicians and authority figures: Twain often satirizes corrupt and ineffective politicians and the authority figures who uphold the status quo. This is evident in characters like The Duke and Dauphin in *Adventures of Huckleberry Finn*.
* Human nature in general: Twain has a knack for finding the humor in the foibles and inconsistencies of human nature. This is evident in his witty observations and the often-absurd situations his characters find themselves in.
It's important to remember that Twain's humor is often biting and satirical, meant to provoke thought and expose societal flaws. He doesn't just make fun of people; he uses humor to challenge and critique the world around him.
To understand who Twain specifically makes fun of in a particular novel, you need to examine the individual work and its context. For instance, in *The Adventures of Huckleberry Finn*, Twain criticizes slavery, racism, and the hypocrisy of Southern society, while in *The Adventures of Tom Sawyer*, he takes aim at the limitations of traditional education and the expectations placed on children.