Who is Tony Endicott from Factotum and what is their importance?

Tony is a gray-haired old man who takes over Henry Chinaski and Jan's seats in the grandstands at the Los Alamitos Racetrack, Endicott boasts to Jan that he makes $60,000 after taxes in real estate. When Jan begins flirting, Henry picks Endicott up by his shirt collar and threatens to push him through the bleachers, thirty-five feet to the ground. Endicott bites Henry's ear and Henry grabs his throat. When Henry pries Endicott's fingers off the bench and watches him plunge, others bury their noses in the racing form. It turns out the murder is a nightmare, although the results of the race are as Henry remembers.