Originally Posted by
Sephiroth
According to the books he already looked like a snake even before he "died". When he returned to Dumbledore he already had red eyes and his inhuman skull and snake-face but not as much as he had in the end. That he was already doomed as a child has been shown in Harry Potter 6. Dumbledore just didn't know that he would become that evil and tried to teach him normally. Still, as he said, if he would have known he would have tried better. Or he probably would not even have picked him up in the Orphanage. Whatever.