Yes, I hate grimlocks, when you descriped it the first thing that poped into my mind was the picture in the DMG and I said out loud, "Ah crap not a grimlock." I guess things that are missing body parts really freak me out. At least casting daylight won't help it at all.
I have a question concerning light, would you rule that creatures with Darkvision also have low light vision? In other words, they can see in color like low light conditions but only in black and white in total darkness.
In relation to your last IC post, Kyran's actions sort of rely on whether or not that angry Grimlock decides to smash in his head or not so...