Until Dawn (spoilers for the game)
 

Just a warning this post has spoilers for the game Until dawn

In this recently released game there are a set of monsters called Windigoes. They come about by being on a the sacred mountain and then eating human flesh. After doing that they begin a transformation into windigoes. Being stronger, tougher and definitely monsters.
While they don't show the transformation because it takes months to happen, it is described in various papers and books through out the game. This includes drawings.
In the game there are 11 male windigoes that were miners that were trapped in a collapse and later rescued only after eating some of there own.
Then there is one who is a female that was part of group you try to keep alive throughout the game.

It was interested because the writings on them have pretty good detail and some of the pictures of transformees are creepy.

Good game, good jump scares interesting transformation premise.

Re: Until Dawn (spoilers for the game)
 

Yup, it is a good game. I wonder if enough people check it out, or at least a few of the right people, we might see someone do a sequence involving that one female Wendigo.