Herobrine

Herobrine is a fictional Minecraft character which originated reported sightings of him in the game. His popularity has grown ever since the first hoax arose. Since then, he has been featured in numerous Fan Fictions, Films, and even official Minecraft media, where he appears as a nod to the fans. Overall, he is the default character skin (better known as Steve), except with no pupils in his eyes, leaving them entirely white.

An Egg's Guide to Minecraft Canon
In An Egg's Guide to Minecraft, he acts as the main antagonist as of Part 12, where a servant of his (a Villager) summons him and tells him that the one he spoke of is there. He does this kneeling before a giant underground statue of Herobrine. The ground in front of the statue collapses and falls into an abyss. Herobrine then floats up, as if asleep, and opens his eyes to reveal his identity. Later, when Steve and Jason arrive at the End Portal, he stops them with a cloud of black mist, making them fly into a wall. He then sends Mobs to pursue them, leading them onto a bridge where they are cornered. Steve throws Jason over the Mobs and breaks the block under him, making him fall into the surrounding pit, but survives. Herobrine sends an Enderman to pick up Steve and orders the other mobs to chase Jason.