I figured since Bethesda is currently looking at all the bugs we're experiencing and making a patch, I should report this. Twice this has happened to me, both times in that deserted area in the south west of the map (the name eludes me at the moment). The first time was with a Bark Scorpion. It was half underground and stuck in place due to collision issues, but when I aimed at it and shot it I saw it had no health. Yet no matter how many times I shot it it didn't seem to die, so I had to toggle the collision, go underground myself and kill it. After shooting it for a while, it eventually died, but it took waaaay too long. The second time happened with a large Golden Gecko. I saw one run at me and when I discovered it had no health in it's health bar, I just used the kill command to avoid getting killed while pointlessly shooting it.

This doesn't really hurt my gameplay experience much but it is a bug and I figured it should be reported. That said, despite the http://www.gamesas.com/index.php?/topic/1123453-opening-cinematic-freezing/page__p__16518220__fromsearch__1&#entry16518220, and despite seeings dozens of severe clipping issues in just the first few hours, my experience so far has been good. I just hope the cinematic bug is fixed before I finish the game in a week or so.

Edit: Thought I should clarify, they do have a health bar, but while normal creatures have several rectangles representing their health in the health bar, these creatures have none.