What's that person on my singleplayer world?

[D9074]

So I was messing around at my singleplayer world when I found that person I don't know who he is. I thought that was singleplayer world, so I tried to turn of the Internet, and the person is still there. So I came close to the person when turned back on the Internet, the person dissappeared. Who is this? 

[EzeWindows7Fav]

his name is herobrine he is a minecraft creepypasta learn about him here or here

[basil]

i seed him in my mancraft warld . 

[Aero7]

kinda fake