Who's There ?: Ghost Players

You are in a cave, a very deep cave. You have been mining for many hours in search of diamonds. It's getting late, you are tired. Suddenly you see a white square in the corner of your screen and it disappears as quickly as it appeared. You swear it looked like the name of another Player, but you brush it off as a simple rendering bug...

But what if it wasn't ?

''Who's There ?'' adds in entities that will sometimes appear when exploring caves. They are invisible and have names that look like the names of Players. They walk around you and make noises to make you uneasy while you are mining.