Powerful ally, deadly enemy!

I have come up with a new creature. It's so new, I don't even have a name for it, yet. Maybe you can suggest one?

The first time this creature came to mind, I saw a dragon running toward a cliff. It was in full battle mode and breathed as it neared the top of the cliff. The creature was at the top, just hovering there. It was a black wispy creature without substance to most of it. The