What will the Aliens in 39 Light Years Look Like?

This little tale unfolding, which some of you may be following, actually has its roots in a story I was writing around fifteen years ago. It's premise was thus:
Aliens known as Tyrrians own slave ships, populated by millions of human slaves, These ships are overrun and eventually destroyed- as is the slavers entire civilisation- by the slaves mysteriously rising from the dead.

Yep, a zombie apocalypse. In space. The story followed a human doctor aboard one of these slave ships as he is helplessly caught up in this cataclysm. Trying to find his daughter, who is out among these alien stars somewhere.
Our hero falls in with an alien soldier, an old, gruff, jaded and almost obsolete piece of hardware named Desster, and a robot called Tewen.
The story was pretty epic, and it never left my mind. It did morph though. I found myself interested in Desster, the old warrior, but now he became stranded on an Earth which has had a zombie apocalypse. This tale now followed an alien invading force as it was annihilated by billions of ravenous undead, and their new struggle to stay alive...
This new premise became my focus, and it is slowly unfolding in these instalments I post here.
One thing never really changed though. The aliens. Tall, rough bark-like skin, rough horns lining their skulls and jawline, four black eyes and hands with two fingers and thumbs apiece.
Something like this:

I'm working on the body and clothing. It will be up soon!