There was a family of black dogs in a run-down neighborhood. A bunch of cruel people killed the mother and all the puppies except one, and that one puppy grew up nearly starving and only got food when he could steal it, and he got beaten and chased off by mean people all the time.
When he was fully grown he turned into a young man, and he didn't know how to talk or how to be a human. He would still steal food, and the same mean people couldn't see that he was a human, they still saw the scrappy dog and still beat and chased him.
A new couple moved into the neighborhood, and they could see the young man was a human and not a dog. They had pity on him and tried to get him to come into their house to feed him and help him, but he was too used to tricks and cruel treatment so he ran away.
He came to the ocean, and turned into a seagull and flew for a long time. He flew near a big yacht, and there were cruel people on it who threw rocks and cans at him. One hit him and it turned him back into a young man, and he fell from the sky onto the boat.
The people made him a slave and dressed him in cast-off clothing, but he was too fearful to do anything but hide from them. Whenever they found him they beat him and ridiculed him.
Then one day an older woman saw him. She was a good person and the cruel ones had kept him hidden from her so they could engage in their mean-spiritedd fun without her finding out and judging them. But when she saw the young man she knew exactly what was going on and she locked the doors to the other parts of the boat so he would be safe from the others, and then began earning the young man's trust bit by bit.
She gave him food and nice clothes and got him to try the pool and hot tub, and she talked to him constantly in a sweet and calm voice, trying to teach him to speak. She got close enough to him that she could touch him, and soon he trusted her enough to let her wash him and cut his hair and shave his beard. Underneath the grime he was beautiful, and the more she cared for him, the younger she got.
Finally one day as she talked to him he smiled for the first time, and when he opened his mouth to speak, the most beautiful and amazing sound came out, and though it wasn't loud, all the people all over the world heard it. Those who were cruel at heart and took pleasure in treating other humans and animals badly turned into trees, and would be trees until their souls became kind and clean. Those who were nice and had tried to help him grew glowing gold wings from their backs and learned to fly.
When the beautiful sound of his voice stopped, the young man was gone.