The Boy with the Paw Print (Harry Potter fanfiction)

Ryuk Shinigami is a pretty normal boy. Except for the strange paw print that has be on his arm for as long as he can remeber. Oh and the fact that he got and acceptance letter from Hogwarts.
Starts in the third Harry Potter book. I guess this is an AU somethings are gonna be different but not too much.
This is my first story ever so if you could go easy on me that would be great! Although constructive criticism is welcomed.
Mild language. You have been warned.