I have to admit I thought that the concept of an "orc" was fairly limited to Tolkien and Lord of the Rings....and then suddenly, they pop up everywhere in both literature and movies.
What is an orc? I'm not familiar with that concept.
Orc
An orc (also spelled ork) is a fictional humanoid creature that is part of a fantasy race akin to goblins. 
While the overall concept of orcs draws on a variety of pre-existing mythology, the main conception of the creatures stems from the fantasy writings of J. R. R. Tolkien, in particular "The Lord of the Rings". In Tolkien's works, orcs are a brutish, aggressive, repulsive and generally malevolent species, existing in stark contrast with the benevolent Elvish race and
between them. The English word is now generally supposed to be derived from Latin Orcus.
Also, in an unpublished letter sent to Gene Wolfe, Tolkien also made this comment:
Orc I derived from Anglo-Saxon, a word meaning demon, usually supposed to be derived from the Latin Orcus—Hell. But I doubt this, though the matter is too involved to set out here.
From this use, countless other fantasy games and works of fiction have borrowed the concept of the orc. 
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