I don't know if Herobrine is in 1.8 and the snapshots, but there is most definately proof (or a few glitches). He is invisible and killed off an iron golem of mine, poped a torch off the wall, breaks my wheat in front of me, etc. if thats not creepy enough, something "invisible" seems to be lurking around my village and attacking mobs at night. Snow golems ans skeletons keep shooting at "noting" in the same exact area as if they were attacked by "him" and they know he is there. I thought it was a glitch but since they all attacked around the same area was freaky, because the skeleton did not see me and it was hostile.