Sapient6
Survivor
they could have very bright, noticeable eyes that you can see from a distance to distinguish them from normal ones
I'd prefer that to the entire body glowing green/blue/orange. I'd even prefer for the eyes to not be so bright that you can tell from a distance, I don't really need the game to telegraph that something tougher than usual is on the way (at least when it's just these slightly souped up variants).