It's not human. Yet.
The Thing (2011) is a sci-fi horror movie. According to Wikipedia, this movie is the prequel to the 1982 movie of the same name by John Carpenter. The 2011 movie's plot takes place immediately prior to the events of the 1982 movie.
Synopsis: A team of Norwegian and American scientists are working together in a research in Antarctica in 1982. Paleontologist Kate Lloyd (Mary Elizabeth Winstead) is recruited by Dr. Sander (Ulrich Thomsen) and together with his research assistant Adam (Eric Christian Olsen), they fly to Antarctica. They discover a frozen alien specimen buried deep in ice near its crash-landed ship. They recover the specimen to the safety of the base, only to realize too late that it's still alive... and it has the ability to consume and imitate the shape of that which it kills.
The main concept of this movie is the existence of an ugly and nasty alien that creates dissension and chaos among a group of people confined in a God-forsaken place such as Antarctica. No one can trust anyone, everyone is in fear, there's absolutely no sense of safety at all, and everything is in complete chaos.
The final highlight is the sense of utter despair and total breakdown of trust among team members because anyone can be the impostor, i.e. the dangerous alien shape-shifter ready to pounce on them anytime.
The CGI is effective with the alien form looking horribly organic and icky. Imagine goo, slime, and pink tentacles swishing around and killing people.
Here's a remark I like from the Internet: "Loving prequel to a horror classic. It's full of chills and thrills and isolated Antarctic atmosphere and terrific Hieronymus Bosch creature effects, and if it winks genially at the plot twists of Carpenter's film, it never feels even a little like some kind of inside joke."
If you like sci-fi horror movies, this movie is for you.