So far, there has been George and Lennie, Crooks, Curley, Slim and Lennie by himself
For themes, there has been: Dreams, Strength, Victims, Animals, Fear and suspicion, and Friendship.
My guess is the only main characters not to appear are Curley's Wife, Candy and George by himself
Themes along the line of Loneliness or Discrimination/Role of Women.
Reply with your predictions!