I don;t think the big guy has a tail, its liley to be some sort of wire or ammunition thread. However, if it was a tail, that character would almost certainly not be Human and therefore not a Spartan. Therefore, he could only be an Elite, because in older generations, Elites used to have tails, although they usually cut them off, thi guy might have left his on :P But in the end, I doubt its an Elite or a tail...