The Mark Twain title character with 6 letters is 'PAUPER'. The PAUPER is a character from the novel 'The Prince and the PAUPER' by Mark Twain. The novel tells the story of two boys who are identical in appearance: Tom Canty, a poor street urchin, and Edward, Prince of Wales. Through a series of events, the two boys switch places and experience life in each other's shoes. The novel explores themes of class, identity, and justice.