 In the opening scene you now see more of the alien. In the theatrical   release we see it fight off one of the cavemen, killing it, and the other   caveman gets up to see it lying on the ground draining out the black blood   (or what fans know as black oil). In the video release, we see it run off   after it kills one of the cavemen, and when the other caveman gets up, he   tracks it down and then kills it using the broken end of his torch. 