Uncle Pumblechook is only slightly above Joe and Biddy in social status, but he acts like he is far, far above them. He is comical because he tries to act like a high class person but cannot pull it off because he is uneducated and talks like a buffoon, using way more words than necessary to express even the simplest of thoughts. His biggest dark trait is that he is a hypocrite. Throughout the novel, whenever he is present, he is a kind of candle in the wind - blowing whichever way the wind blows. In the bar, when Jaggers makes a fool of him, he first says one thing, then another, depending on whose opinion is being expressed, and Jaggers calls him out on it, proving what a blowhard he is. When Pip comes into his money, Pumblechook sucks up to Pip as if he is the richest man alive. At the end of the novel, when Pip returns after having lost his money, Pumblechook treats him poorly again, just like he used to when Pip was a boy. Pumblechook is a slimey character, a phony.
Uncle Pumblechook of Charles Dickens's Great Expectations is the stereotype of the shallow class-obsessed and envious man who is also a hypocrite and one who exploits others; he is comical in his pompous fatuity. In fact, he has no redeeming characteristics. For one thing, he never displays any affection for his relatives; during Pip's lifetime, there is no love or kindness or real concern for him ever shown by Pumblechook.
When, for instance, Pip is taken to Satis House on his first visit, Pumblechook tries to sidle through the entrance gate with him, but Estella prevents his doing so. While Pip stays at Pumblechook's prior to this visit, the corn chandler spends his time enviously watching the other merchants and feeds Pip a most meager supper. In the morning Pumblechook, whom Pip considers "wretched company," gives Pip "as much crumb and as little butter" as he can for a breakfast.
After Pip is visited by Mr. Jaggers and informed that he has "great expectations," Pumblechook fawns over him, saying, "I wish you the joy of money," thus demonstrating his value of wealth over any joy for Pip himself. Indeed, Pumblechook is, as Pip describes, "the basest of swindlers" for, unlike Joe, who has a strong sense of the virtue of industry," Pumblechook seeks only monetary gain and elevation of his social position. For example, in Chapter XXVIII, Pumblechook "swindles" and exploits Pip by claiming the credit for Pip's wealth as being the one ("the patron") who introduced him to his supposed benefactor, Miss Havisham.
Having read the newspaper that lauds Uncle Pumblechook, Pip realizes that he has been exploited for Pumblechook's social gain. With wry humor, he remarks,
I entertain a conviction that...in the days of my prosperity if I had gone to the North Pole, I should have met somebody there...who would have told me that Pumblechook was my earliest patron and the founder of my fortunes.