I once was in a U cave (the one that you find that has two entrances and is shaped like a U) and I was exploring caves for ores, when Herobrine (or so I think) pops up 6 blocks away. It was my first sighting, and I wish I had taken a screenshot, but instead I screamed and logged off immediately. I came back a few seconds later, and he was gone, obviously. I continued what I was doing, and never saw him again.
Reply if you have been in a similar situation.
