Naoko, there is not even the need to ask, it’s obvious. Firstly, Sirius is an animagus, a person who can transform into a dog at his will, NOT a werewolf, Remus Lupin is a werewolf. Secondly, Prisoner of Azkaban in which Sirius first transforms was published in 1999, New Moon where Jacob first transforms was published in 2006. So unless your brain cells have been damaged beyond repair from reading Twilight, you should be able to discern the fact that even if any copying has been done it would be the other way around, Jacob based off Sirius. As to why people like Harry Potter more, it’s because they are sane, which is more than what I can say for you. Harry Potter has a story(and an awesome one) while Twilight… I can’t say it without seeming rude. Harry Potter has a beautiful characterization which shows how diverse human ways are while Twilight is… frankly and aptly put, dumb.