Who is Dodson and Fogg from The Posthumous Papers of the Pickwick Club and what is their importance?

Dodson and Fogg are the lawyers handling Mrs. Bardell's lawsuit against Mr. Pickwick. When she is unable to pay their fees, the two men have her imprisoned as well. Fogg and Dodson are described as greedy, immoral men. Mr. Pickwick calls them "a well-matched pair of mean, rascally, pettiflogging robbers."