The Gift of the Magi
Madame Sofronie to Della
Madame Sofronie is not an antagonist, but she does represent the wrong way of valuing things (in the narrator's opinion): she's only in it for the money. We see this in the transaction over Della's hair. Whereas to Della her hair is a unique treasure with a special meaning, to Madame Sofronie it just means another $20. And whereas Della is warm in character, Madame Sofronie is "chilly" (12).