The unnamed ugly duckling lives an unpleasant life in the "duckyard" of the farm on which his family lives. With the notable exception of his mother, he is not only disparaged for his looks, he is often bullied and brutalized.
Away from the farm, he finds himself in the wild. The wild geese treat him better, inviting him into their world, but just as his hopes rise he and the geese are set upon by hunters, and only he survives.
He seeks refuge in an old woman's hut, but the woman's pets - a cat and a chicken - make life unpleasant for him. So he heads back out into the wide, wild world and finds himself alone on the brink of winter. The cold weather nearly kills him, but as spring arrives, he finds himself feeling stronger and flies to a beautiful place with a collection of regal swans.
The ugly duckling has by now given up on life. He intends to place himself among the swans and then expects them to simply kill him. Instead, they recognize him as one of their own. Looking at his own reflection in the water, he sees that he is! In fact, the little children who visit the garden think him the most beautiful swan of all.