I don't know what it is but it's weird and pissed off
The thing to remember about The Thing is that it's all guy talk. There are no women in the U.S. scientific outpost in the South Pole, just men, getting on each others' nerves, exploiting weaknesses mercilessly, getting drunk, stoned, inflicting their differing musical tastes on each other, reduced to watching videos of old Let's Make a Deal episodes. Truly, this outpost is a bad gig.
One day a couple of crazed Norwegians land a helicopter at the base after chasing a dog across the tundra, shooting at it with rifles, machine guns, finally lobbing grenades at the poor thing until, upon landing, one accidently blows himself and the helicopter up with a dropped grenade. The other is shot dead by the U.S. camp commander after spraying the place with gunfire trying to kill the mutt. What the hell has got into these nutty Norwegians?
Well. it came from outer space, many years earlier, and has been buried under the snow and ice. The Norwegians dug it up and now it's on the loose. What does it want? Nothing conscious but what it does is invade the body of human or animal in various graphic FX ways before perfectly imitating the host being. So, once the thing's MO is sussed everyone suspects everyone else of being a murderous alien and what little social cohesion has kept these guys from killing each other breaks down completely.
John Carpenter's movie is a re-make of Howard Hawks' 1952 original and I can't say which is better because I haven't seen the original. However, despite Hawks' version being rumoured to have been script doctored by Ben Hecht , you couldn't swear in the movies in 1952 and if you were confronted by a shape-shifting alien which invades your body before exploding out with a spray of goo and gore you'd probably be swearing your head off. This, I suspect, gives Carpenter the edge.
The script is by Bill Lancaster, based on a short story called Who Goes There by John W Campbell, the photography is by Dean Cundy, the score, all throbbing doom and grandeur, is by Ennio Morricone and the special effects, maybe the best in horror movie history, are by Rob Bottin. Here's the cast; Kurt Russell is MacReady, Wilford Brimley is Blair, TK Carter is Nauls, David Glennon is Palmer, Keith Davis is Childs, Richard Dysart is Dr Copper, Charles Hallahan is Norris. Peter Maloney is Bennings, Richard Masur Is Clark, Donald Moffet is Garry, Joel Polis is Fuchs and Thomas Waites is Windows. They say each other's names constantly throughout the movie because they're good movie names that sound good when you hear them.
Jed the Dog plays the lead dog. All the dogs are good but Jed turns in a bravura performance- watchful, intense and duplicitas with a great actor's timing.
There are elements of paranoid classic Invasion of the Body Snatchers and also of the famous Alien scene where the monster first appears out of John Hurt's chest. The Thing isn't as good as those two (or three if you count the 50's original and 70's re-make of Body Snatchers) because it's all guys. Stupid, nasty, bored shitless guys who are forced to have to save the world from...what? The thing.