I wanted him to be able to travel without the loud pop of apparation. He needs to be silent and stealthy. He needs to be nothing more than a shadow upon the wall. Thus, he not only is a shadow, but he shall utilize them, as well.
Thanks very much! More shall likely be soon, with any luck. I think I'm all excited about doing this because it's combing Snupin with one of my other all-time favorite things. Heeee.