This does sound like a skin walker, which is a Navajo belief. One is not supposed to talk about it as that attracts these things. Since I am part native I would also prefer not to talk about it as this is very scary for me, but I also want to help.

These things are indeed shape shifters and from what I understand they are negative. They get seen regularly around the Navajo reservation but nobody likes to talk about it. But some people do and that's why it's known that these things get seen.

I don't know much more about these creatures as I don't really want to know. I live alone and I'm scared as it is, lol.