Herobrine

Herobrine is the subject of an old scare-story, where a person with the default skin, and completely white eyes appeared in singleplayer games.

There is speculation that he is actually a painting of the default skin with no eyes, but no proof exists. This originates a long time ago, when a "creepy-pasta" was made about Herobrine.

The creator of the stream "Brocraft" who goes by the name "Copeeland", along with his friend, "Patimoose" Have both seen Him on stream. Herobrine was first seen in the Brocraft stream (at 20:45).

there was another video where herobrine was in the middle of Patimoose's lava field. Patimoose then went back up the stairs he went down. Saved and quit. He came back 10 minutes later after a beer and some time to cool off, where there was another sighting. Brocraft stream. In this sighting Herobrine appears in a area Patimoose had previously walked through discounting the painting or door theory. Patimoose's wife asked if he wanted some cake and he said "no thank you". A couple seconds later TurqouiseCrayon, another brocraft streamer in vent said "in busy trololing about 74 people". People often times think turqouises voice is Pattimoose's and cite this as proof it is a troll when really Patimoose never said it was.

Most of the video consists of Patimoose getting reactions from everyone that was in chat. At the end of the video Patimoose crashed his game because he couldn't stand getting close enough to him.

After his game "crashed", all members then saw this page, featuring the default Minecraft face with real eyes in the place of the blocky eyes.

There are a couple theories on how they created this prank if it is a prank. One theory is that it was a reskined painting, while another theory is Patimoose and Copeeland changed the iron door texture. However, neither of these is a possibilty as In the third video Herobrine appears in a place that had been previously walked through

Possible future update
Notch has posted on twitter about the subject of Herobrine.

Although this may confirm that there is no Herobrine, it suggests that Notch may plan to add him as an entity in the near future, presumably acting in a similar way to the faked Herobrine. Another possibility is that notch may be trolling or that it may be a glitch