Phys X has a really uncanny ability to pick a random prop and make that the loose pebbles that bounce around everywhere once something is hit. First video looked like a giant spider, reaper, thingy. SOE, get on it (both the bug and the concept.)
What the eff? What am I even looking at? Where does that model even come from? Are those biolab legs? Also, hell yes to those giant spiders. Forget BFRs, let's have an entire large base walking around on gigantic metal legs.
I experienced a similar phenomenon with physx (usually with rocks or plants) that would happen frequently. I was forced to disable PhysX b/c of it and haven't really tried it since, but it stopped when I disabled physx.