Herobrine

Herobrine is the brother of Notch and one of The Lords Of Minecraftia. He is often referred to as a CreepyPasta, and also a myth. However, he is all too real. He is the true Ruler of Minecraftia, a title which was taken from him by his brother. He is also part of the Guardians. He looks like Steve, and was mistaken for him by the fatass, but the only way to tell them apart is that Herobrine has those dark... lifeless... eyes...
 
He is extremely powerful. He can fly, throw fire, has extreme reflexes (such as catching arrows in midair), and can run faster than a sugar-hyped Super Sonic. Notch tried to kill him once, and framing it as an accident. Of course, it failed. Herobrine died, but still survived (don't bother asking me how).
His nemesis's true name is not known, but it goes by the name Entity 303.