20 Things You Didn't Know About Halloween (1978)
12. Black Christmas (1974)
Fans of Halloween may also be aware of Bob Clark's 1974 film, Black Christmas, in which an unseen killer stalks and murders the members of a sorority house during a Christmas party.
John Carpenter was also a big fan of that film and had originally asked Clark for his permission to make a sequel to it, as well as asking Clark for any ideas that he may have had for it.
Carpenter had pitched Halloween as being a sequel to Black Christmas with the killer from that film having been captured, but escaping in order to terrorise the new residents of the same sorority house, albeit on Halloween instead of around Christmas.
However, the project then morphed into a story about babysitters being stalked and murdered. Whilst it is a similar premise and the fingerprints of Black Christmas can be seen on the finished Halloween film, Bob Clark acknowledged that Halloween is its own animal.