Chapter Text
Izuku Midoriya was diagnosed quirkless at age four. He had an extra toe joint associated with quirklessness. Little did he know that the doctor neglected to mention the other thing that the toe joint was associated with. Avian quirks. The reason the doctor did not mention this was that Izuku did not have any obvious mutations. This would come back to bite the man in the future.
Izuku was six years old when he noticed that the nails on his hands and feet were a bit harder and sharper than those of his classmates. He wasn’t sure if it was a quirk or just something that ran in his family, so he didn’t bother to bring it up to his mother, or anyone else for that matter. When he was ten he noticed that he had rather sharp teeth, more designed for eating meat than vegetables and fruits, as he’d learned in science class. He was fine with that, he liked meat more anyways. He also noticed that his hands were looking different, and his feet also looked rather different.
When Izuku turned twelve, all the things he’d noticed over the years after each of those two instances culminated in a solid theory. He had a bird mutation quirk. The new nubs that were growing on his back seemed to corroborate this theory. They were tiny, slightly feathery stumps on his back, growing from his shoulder blades. Despite how small they were, they made it very difficult to sleep on his back, and he found himself sleeping on his side more often than not. When his mom found out, she was ecstatic. It must be a combination/mutation of her and Hisashi’s quirks, she thought. She hoped that this would be enough to bring Hisashi back. His son had a quirk after all, and the man could no longer think the boy was useless. Inko had known all along that Izuku was an amazing kid, maybe now her husband would see that too.