the thing (1982)

aka John Carpenter's The Thing.
The Antarctic and a number of Norwegian scientists in a helicopter are pursuing and shooting at a husky, crashing outside an American base. The Americans take in the dog and investigate the Norwegian's base. Finding death, destruction and a hideously mutated and burnt corpse. Only when the dog mutates do they realise that there is an alien parasite in their midst, and worst of all, any one of the camps inhabitants could already be infected.
This adaption of the 1950s Thing From Another World, a masterpiece of cold war horror, is updated with modern special effects, ramping up the gore, as well as the paranoia. A classic example of how to re-make something and get it right by John Carpenter. Who was on top of his game at this point.