There are a few different types of shapeshifting. The most common of course is that like what happens to the werewolf – where the body actually goes through a metamorphosis and actually changes into a different configuration. It is typically a painful process that involves the entire structure of the being changing – bones, skin, structure all take on a different shape. A second type of shapeshift is when a being can just switch between two bodies without having to go through a physical transformation at all.
Interestingly, there is third type of shapeshift which involves another layer of skin and flesh growing on top of the existing person or animal. This type of shapeshift is called the “fold over”. It is said that it is typically a pretty painless process as the actual configuration of the being does not change. In a sense, it is just a “second skin” that spreads atop the original.