This Mysterious character Is Named Herobrine Assassin or before he was a Assassin named Bryan. He is mysterious because he would usually spawn in any of your worlds and creep up villages and kill all villagers so you can't trade. He is also known for going to to random servers like Mineplex or Hypixel to control your character and kill you all the time then crash your Minecraft! He is called Herobrine Assassin because he has very bright white eyes under his hood. It is unknown why Bryan got turned into Herobrine Assassin. All developers of Minecraft are trying to stop him but not yet in the new update. Beware of him! If you see him then contact notch. :O Oh and Also He has poisoned Arrows so be careful if you end up battling him.