How are they like the djinn, out of curiosity?  As far as I know there isn't too much intertwined there other than the djinn being mischievous and being able to change form.

  types of djinn:

 One type flies through the air, another type consists of snakes and dogs. A third is based in one place but travels about.

ur shadows are kinda like the ones that fly thru the air.

And only some people can see them. But most people cant.

yeahhh i dunno thats about iyt. It just came to mind like that. Theres probably lots of different names for em..

[Shadow]

Anyone can see a shadow if they are following you.
But only a glimpse.
It's just a matter of taking notice.

hmmmmmm is a shadow also called a shade?

[2gunsdrawn]

I think the term shade is usually used to refer to a ghost. I'm saying this because if you read alot of old books (like the Aenneid, the Oddyssey, the Divine Comedy, etc), they never say ghost, they almost always say shade. But I don't consider myself an expert on the subject, so if I'm wrong, someone please let me know.