Disclaimer: the only thing I own is the creature Harry is because I made it up. The rest belongs to the wonderful J.K. Rowling!
Sitting alone in his tiny room at Number 4 Privet Drive, Surrey was Harry Potter. It was July 30th 11:00pm. "One hour to go", Harry said softly to his snowy owl Hedwig.
He sat there trying not to think of the first 'punishment' the Dursleys had given him this summer. His back was bruised and bloody, his chest was even more bruised than his back and he might have some broken ribs but has no way to know for sure.
The summer had started as usual with him being ignored, but then he had dropped a cup while setting the table and all hell broke loose.
Vernon jumped up and started screaming, calling Harry a useless and ungrateful freak, while advancing on the terrified boy.
Harry tried backing away but forgot there was glass on the floor and stepped in it with his bare feet. Crying out in pain he fell to the floor. Looking up at his uncle's face that was purple with anger. Vernon had on the malicious grin that had been becoming more and more frequent.
Harry was about to be beaten. There was no other explanation. The beatings hadn't started until he started Hogwarts School of Witchcraft and Wizardry an had been getting worse ever since.
Upon seeing the gleam in his uncle's eyes he knew he couldn't get out of this and it would be the worst yet. Seeing his uncle pulling back a fist, Harry cringed and curled into a ball.
Blow after blow was landed on Harry's back, face, and chest. By this point Dudley had joined in kicking him viciously in the ribs. All the while Harry was laying on the broken glass.
Petunia threw a frying pan, hitting him in the head, and the world went dark.
When Harry had come to he was sprawled on the floor in front of his bed. They had simply thrown him in the room and locked him in. There had been many more beatings like this one and it was all Harry could do not to break down. If he did that his magic could lash out. His magic was getting more out of control as his birthday drew near.
Another ten minutes passed before the first owl arrived snapping Harry out of his reverie. Two others soon followed. By 11:30 Harry is sitting on the edge of his low bed with his birthday presents in a neat row in front of him. Rock cakes from Hagrid, a book on Phoenixes from Hermione, and a renewed subscription to Quidditch Weekly from Ron.
Harry smiled faintly at the predictability of his friends and fed some of the rock cakes to Hedwig. Hagrid was nice but Harry had no desire to lose his teeth trying to eat them. Looking at the clock it was now 11:55. "Come here Hedwig, I need to send out these thank you notes", Harry called softly to his owl.
The clock struck twelve just as Harry shut the window, Harry screamed. Pain tore through his body. The pain was worse than all the beatings combined. Still screaming Harry fell onto his bed, body convulsing and changing. Wild magic exploded out of his every pore, it was felt by the whole block. It also set off the wards around the house.
By the time Harry stilled he was transformed. His hair was thicker reaching just above his shoulders. His face was now heart-shaped and his frame has filled out but it was slightly feminine with a narrow waist. However Harry knew none of this for he had passed out from the pain.