Was the creature in "The Thing" supposed to be a "gray" alien that got thawed?

The Thing was filmed in the early 1950s, before UFOlogists babbled about gray aliens. It does not at all resemble them, anyway. The role was played by an actor who later became very well known for a different kind of role. The movie is based on a short story by John W. Campbell, Jr., then the editor of Astounding Science Fiction magazine, titled "Who Goes There?", and he certainly would not have catered to UFOlogy nonsense.