The first time I saw this I just about died. This is a banner, an incredibly rare movie poster that is not even listed in the campaign book. A movie poster dealer friend of mine found this for me back in 1993 I think, and since that time I've only ever seen one other example.
Banners are approximately 25"x82", so as wide as a three-sheet is tall. Made of the same heavier stock paper as half-sheets, they are rarely found unfolded since they are so long. And again with the funky color scheme, although in this case the printing is using a reduced 3-color process. It does carry the NSS number on each edge.