A self-described man-child, Skimpole is a parasitic mooch who lives a life completely free of responsibility. Claiming to understand nothing about money or other adult matters, he is clearly a phony. He eventually betrays his main patron Jarndyce.
Bleak House has many very realistic and sympathetic characters, but Skimpole is not one of them. He is a leech who pretends that he is just too naïve and charmingly childlike to understand responsibility. In reality, of course, he is way too clever for any of that baloney to be true.
Shmoop sees two reasons for Skimpole to be in the novel. The first is kind of a biographical fun fact: Skimpole was actually an unflattering caricature of a guy named Leigh Hunt, another Victorian writer. Apparently, when the book came out, everybody in the know immediately recognized Hunt as the horrible Skimpole. As you can imagine, Hunt wasn't too thrilled, and he and Dickens went from frenemies to full-on enemies.
OK, Shmoop, enough old-timey gossip, move along already. The second reason for Skimpole's existence is the way he puts kind of a strange negative light on Jarndyce's generosity. It's great that Jarndyce is such a nice guy, and it's probably a good thing that he supports Skimpole's wife and children, since Skimpole is unlikely to. But why does Jarndyce constantly excuse Skimpole's clearly awful behavior? Why does he, against all reason and evidence, accept Skimpole's shtick about being a grown-up child who doesn't understand money? Might there be a connection here with that other thing Jarndyce tries to ignore as much as possible, the Chancery lawsuit? Check out our analysis of Mr. Jarndyce for some more thoughts.