Who are the supporting characters, the flat characters, the round characters, and the protagonist characters in "Misery" by Anton Chekhov? Are any...

The protagonist Iona Potapov is virtually all alone in the big city of St. Petersburg. The men he encounters are all strangers. There are no women in the story, either with other women, by themselves, or with male escorts. There can be no supporting characters unless one wants to classify Iona's horse as a supporting character. The other characters are all flat. Four of them are passengers Iona manages to pick up in several hours on this cold, snowy night.

The only interesting one is a hunchback who accompanies two other young men. All have been drinking and are "out on the town." The hunchback is cruel to both Iona and his horse. He encourages Iona to whip her in order to make her trot faster. The reader senses that the hunchback feels vindictive and cruel because he has suffered all his life from his deformity. He insults poor Iona and hits him on the back of the neck.

"Tfoo! the devil take you!" cries the hunchback indignantly. "Will you get on, you old plague, or won't you? Is that the way to drive? Give her one with the whip. Hang it all, give it her well."

Iona's mare can hardly be called a rounded character, but we feel affection for her, just as Iona does. She is quiet, patient, forbearing, and even seems sympathetic. She is Iona's best friend, probably his only friend in the city. We can understand why he would be reluctant to whip her when she is probably underfed and is pulling the sledge loaded with the driver and three passengers.

It would seem that Chekhov intentionally depicts all the other characters in the story as indifferent strangers in order to emphasize the pathetic ending, especially to contrast the little horse with the humans. She may not understand the words she is hearing, but she seems to understand the tone and the feelings he wishes to convey. She has suffered all her life and can understanding suffering.

The little mare munches, listens, and breathes on her master's hands. Iona is carried away and tells her all about it.

Iona is using figurative language, an analogy, when he tells his horse what has happened and how he feels.

"Now, suppose you had a little colt, and you were own mother to that little colt. . . . And all at once that same little colt went and died. . . . You'd be sorry, wouldn't you?"

This is extremely touching. Chekhov succeeds in communicating the sledge-driver's grief although the man was unable to do it himself.