Herobrine

Herobrine is the subject of a community-made "creepy-pasta". He is a human entity, but with white eyes, and often seen as a dead miner.

The story behind Herobrine
Herobrine creates random constructions, such as pyramids and long 2-block-high tunnels. He also burns down, or cut off leaves from trees, and creates cobblestone-complexes underground, much like dungeons, lit with redstone torches. He often appears at the edge of fog, in a tiny render distance.

Variations
There are many variations of Herobrine's behaviour, but they usually fall under two categories.

The stalker version of Herobrine is Notch's brother, who stalks the player, disappearing if approached.

The miner version of Herobrine is a vengeful miner that tries to ensnare the player in traps, presumably to steal their items. He waits for people to enter his dungeons, then either seals them inside, or "teleports" behind them, presumably killing them. Some variations of this particular version says he breaks the player's creations, and steals their items from chests.

Origins and popularity
Herobrine first appeared in a single image detailing an encounter. It was posted on a thread in the forums, and gained very little attention. It stated how Herobrine had appeared in someone's single-player game, littering the map with various pyramids and tunnels.

It was only later that Herobrine grew in popularity, when the Brocast staff staged a hoax in one of their live-streams. Herobrine was introduced to the stream here (at 20:45).

Later on, there was another video showing Herobrine in a user-made lava field. The livestream went down after the player ran and saved, only to resume ten minutes later, where Herobrine had disappeared.

During this stream, the player can be heard talking to his wife, stating he was trolling, which flooded the livestream chat with outrage. The player then faked a game crash.

During this crash, all watchers were redirected to another page, featuring Herobrine's face, but with real, frantically rolling eyes in the place of his block eyes, modified to be completely black.

When viewing the page's source, there were a jumble of characters and letters. after removing all non-alphabet characters, the following message was revealed.

The message keeps telling the viewer to "wake up", implying they're living in a fantasy world, and this text hidden in the page is their "note".

It is widely believed all of his appearances in the stream and outside are retextured paintings, retextured iron doors or other players, albeit with the name tag removed above their head.

Since then, there has been a huge increase in his popularity, propelling Herobrine to meme status, making moderators of the wiki and forums need to take extra steps to stem the flow of user-made spam.

Future update
Notch posted on twitter about the subject of Herobrine, early in his popularity boost.

This confirmed there was no Herobrine, but suggested Notch planned to add him at a later date.

At Minecraftcon 2010, Notch confirmed Herobrine will be in the game, probably in a "seecret friday update".

Due to increased drama surrounding the Herobrine page, a wiki moderator asked notch over IRC if Herobrine would be added:

This shows Notch has decided against adding Herobrine. However, the fact that "as is" suggested that something like Herobrine may be added, fuelling beliefs he will be added even further. So, once again, the same user asked for clarification

Mojang media appearences
Herobrine has appeared in official Mojang images as an "in" joke.

His first appearence in official mojang images started with the Wedding Weekend, in which he was just behind Notch's Minecraft character. His second appearence was in the Minecon header, where, yet again, Herobrine was just behind Notch.

Some users point to this as proof of his future addition. However it is likely a Red Herring, and only there to provoke Herobrine "supporters".

Changelogs
Herobrine was stated to have been removed in Minecraft Beta v1.6.6. This was a joke, referring to Notch removing the Human mob.

He was also stated to have been removed in 1.7, as well as 1.7_01, this time with no reason apparent.