Fringe: Spot "The Observer"

Anyone watching Fringe is keeping a sharp eye out for The Observer, this mysterious figure who randomly appears in the scene of the crime.

This site has more information about him. And this video below compiles all of his appearances so far.

And honestly? The video scared the crap out of me, eventually. Someone reeling on every scene like that? Like a ghost but not really a ghost? Creepy!