Tiny Tim is an innocent victim of poverty designed to make the viewer or reader sympathetic.
There are hundreds of movie versions of A Christmas Carol, but the basic plot is the same in most of them. Tiny Tim is one of the most popular characters in the book or movie. He is cute, crippled, and sweet. What’s not to love?
Tiny Tim is Bob Cratchit’s youngest son. Scrooge seems to have no idea of his existence, or of the existence of the rest of Cratchit’s family. When the Ghost of Christmas Present takes Scrooge on a tour, he stops by the Cratchit place. Scrooge becomes enamored of Tiny Tim almost immediately. He is described as good by his family, and he makes an absolutely adorable blessing. Scrooge worries about him because he is crippled, and asks the ghost if Tiny Tim will live.
“I see a vacant seat,” replied the Ghost, “in the poor chimney-corner, and a crutch without an owner, carefully preserved. If these shadows remain unaltered by the Future, the child will die.”
“No, no,” said Scrooge. “Oh, no, kind Spirit! say he will be spared.” (Stave 3)
When Scrooge goes to the future, he learns that Tiny Tim died and watches the family mourn him. He is very sad to learn this, especially since in his mind he is reformed. The new Scrooge cares a lot about people, especially Tiny Tim. He should have helped the boy.
There is something about Tiny Tim that is symbolic for Scrooge. The boy reminds him of his lonely childhood. He is sympathetic toward him, and comes to care about him as if he was his own son. He keeps his word to Bob Cratchit that he will help the family.
[To] Tiny Tim, who did not die, he was a second father. He became as good a friend, as good a master, and as good a man, as the good old city knew, or any other good old city, town, or borough, in the good old world.
Like the other two children, Ignorance and Want, Tiny Tim is an innocent victim of poverty. Dickens is making the point that people need to look out for each other through children. Tiny Tim is a perfect symbol of the vulnerable. He is a very effective reminder that everyone deserves a better life.