Below you will find a link to the complete character analysis at eNotes. Here are the major characters, excerpted, so you get a quick idea:
Ella may best be characterized as repressed. She tends to ignore the things going on immediately around her. It is clear, though, by the way she will just as quickly return to a topic, that she is simply trying to keep things under the surface.
Ella is the mother of the family in Curse of the Starving Class.
Ellis represents the greed of the petty business owner and the tendency of people to take unfair advantage of each other.
Ellis is the owner of the Alibi Club, the bar where Weston spends his time. He is greedy and seeks to take advantage of the family. He comes to the house to claim it.
Emerson is a broadly drawn "bad guy" who is reminiscent of thugs in old time gangster movies. He is not very complex; a rather two-dimensional character.
Emerson is a small man to whom Weston owes money. He appears, with Slater, at the end of the play, when he blows up Weston’s car. He is menacing and laughs at the family’s plight.