The Hatbox Ghost is the Great White Whale of Disney Haunted Mansion fandom, a remarkable spook-house effect (a ghost holding a hatbox has his head disappear and reappear in the box) that didn't work well in the ride. No one has been sure if it ever made it into production — if anyone apart from Disney employees ever saw it in action — but now, for the first time, footage of the actual Hatbox Ghost in the actual Haunted Mansion during general admission has surfaced. I am STOKED.
Update: Derp, I posted this in 2011! Shows you how beat I am after Comic-Con. Wizard needs sleep, badly.
Disneyland History 1969 – Mystery of the Hatbox Ghost