The Thing From Another World is the first and one of the best monster-alien movies (1951). It is based on John W. Campbell's "Who Goes There?" In it, a humanoid vegetable arrives by spacecraft in the Arctic and terrorizes the inhabitants of a base.

 

The titular monster was played by James Arness, best known for his long-running role as Marshall Matt Dillon in the TV series Gunsmoke. His impressive height of 6 feet 7 inches had barred him from becoming a naval fighter pilot in World War II (the limit was 6' 2") but made him ideally suited to the role of the intimidating creature whose spacecraft had crashed in the Arctic ice. Arness also appeared in another classic sci-fi movie, Them!, in which he portrayed FBI Agent Robert Graham.