Well, Ripley is the one with the big scratch on her forehead. No, that's more of a gash than a scratch, and it's more on the nose than the forehead, so that one must be Nixon. You can also look at the thighs. Ripley's lacerations tend to run parallel to the bone while Nixon's thighs are shredded in a more perpendicular manner. Also, Ripley has taken off two toes while Nixon is missing her left ear. What? Their fingernails, I guess. No, I think we just use a regular washcloth. I don't even think they even make loofahs out of barbed wire. Knife fights? I don't know. It's not like I watch them every second of the day.