 To use alternate skins, comment out (//) the head and body images in "actors.ini" and delete the doubleslash before the skin you want.

The skins are:

Spikes- Extra spike power 0:
Glow- It... Glows
Military- A quite different design. Equipped with an industrial guillotine!
Gold- It's... gold plated. And highly polished. DON'T SHINE A LIGHT ON IT. It's like looking into the sun. Three of our engineers went blind while making this model.

And you can mix and match, like those books you got when you were small with the little flaps, where you could make a zombie-vampire-knight.