Video not sped up. This thing is fast....when I shine the light on it, it just sits there for a few seconds, then bails into the sand or a hole in the LR. After reading a lot about bristleworms and looking at pics and vids over the last week or so, I'm inclined to think it's not one either. It doesn't have the "bristly" legs like the pictures I've seen.
My first guess about 10 days ago was that it might be a type of Eucinid worm. This really freaks me out thinking about this being a possibility.