Whoever Billy is, you never see his name amongst those classic horror icons (Jason, Freddy, Michael). But really, they all have NOTHING on "Billy". I came across Black Christmas by chance a few years ago on TV and was totally freaked out by it. I'd seen plenty of 70s slashers but never had I seen (or heard) such a scary villian who attacks with a phone more than anything else.
The film opens on a Sorority house that is clearing our for Christmas. However, as some girls leave, one man enters... What starts out as something harmless (some VERY obscene phone calls) soon becomes terrifying as a lunatic begins to kill of those in the house.
What makes this so chilling (like many slashers) is the gradual build up and increasing death toll aswell as the hard-to-listen-to phone threats. However, what sets it apart is how a lot is left unearthed, unanswered or unknown. Bodies are never found, killings are never shown (too much) and we never QUITE know who "Billy" was. I love it when a film is never totally resolved.
The characters are all likable and well-performed, including Olivia Hussey's Jess (the lead) and Margot Kidder's Barbara (the fun-loving foul-mouthed girl). But the scene stealer is "Billy" who acts out twisted domestics in the attic with dead bodies and muliple personalities. These moments are definately the most chilling and will certainly keep you awake at night.