Mobsters

"Cole Phelps: You distribute for Lenny Finkelstein. You're a patsy for those mobsters. Ray Buttowski: Yeah. Big Dog Tom gave you up as his supplier. He says that you're Lenny's sissy and that you'll do whatever Lenny tells you."

— Phelps and Buttowski have Ottie in their grasps now

Mobsters are, as the name implies, characters in criminal organisations. They can be either Italian, Irish, Jewish, Greek, French or Eastern European crime families, Latin American cartels, Chinese Triads, or Japanese Yakuzas. They are usually of higher social class than gangsters, which is obviously benefited from illegal activity and may have entire states or police forces in their pockets.