My Duck Is Dead

An American scientific expedition to the frozen wastes of the Antarctic is interrupted by a group of seemingly mad Norwegians pursuing and shooting a dog. The helicopter pursuing the dog explodes, eventually leaving no explanation for the chase. During the night, the dog mutates and attacks other dogs in the cage and members of the team that investigate. The team soon realizes that an alien life-form with the ability to take over other bodies is on the loose and they don't know who may already have been taken over. 

The film is terrific on many levels. It works as your straight monster or action type film, as a horror/sci-fi and also as a very intriguing look into the human psyche. The incredible sense of paranoia, mistrust and fear, lent not only by Carpenter's direction (which is stunning) but also by the incredible acting of the cast in general. Kurt Russell (obviously) is spectacularly understated in the lead role of MacReady, and, as a direct result he "feels" like a real person, rather than a hollywood "all american hero". The other cast members all carry off their roles with style, and the net result is an intensely believable atmosphere, and a truly fantastic film.