Continuity mistake: In the scene where the lion is trying to get into the tree where Val Kilmer's hiding, it flashes to the lion, then Pitt, then the lion again. On the first lion flash its face is clean, then on the second lion flash its face is covered in blood.
Continuity mistake: After they find Remington's remains in the field, Patterson turns and begins to walk away. As he does so, he lower his rifle. In the next shot, he's holding it up again.
Chosen answer: The darker one is darkness, the lighter one is ghost.