Marla Singer is another main character and a sort of catalyst for the emergence of fight club as well as a distraction from the reality that Brad Pitt and Edward Norton are the same person. Marla seems to be the same age as Tyler (both of them) and does not appear to have a job. Throughout the movie she nonchalantly steals things she needs from unsuspecting victims and describes herself as living in poverty. Her depression leads her to support groups as well as a suicide attempt, both of which bring her closer to Tyler.
Though Meat Loaf’s character Bob is featured as a main character I believe that he better falls into the role of one of the members of fight club, who as a group are set up to be almost identical and can thus be considered the fourth main character in the movie. They are what Brad Pitt describes as “an entire generation pumping gas and waiting tables; Slaves with white collars. Advertising has us chasing cars and clothes,