It's been some time since I've read the series, but if I remember correctly, Breaking Dawn stated a shapeshifter becomes whatever animal they are focusing on when they first become a shapeshifter. ...It was something along those lines.
(Of course, that's merely fiction! Ha! But still, that's what I remember the book saying nevertheless.)
Based on the fact that this is the first time I've heard of it, yes. lol. Again, it's been awhile since I've read the books, so there could be a teensy bit of a fallacy in my response.
I don't think so. If he could have, then during the time were Billy was telling their ansester's story he would of said that they were able to change into something else.
