An orc (sometimes spelt ork; /ɔːrk/), in J. R. R. Tolkien's Middle-earth fantasy fiction, is a race of humanoid monsters, which he also calls "goblin".
In Tolkien's The Lord of the Rings, orcs appear as a brutish, aggressive, ugly, and malevolent race of monsters, contrasting with the benevolent Elves. He described their origins inconsistently, including as a corrupted race of elves, or bred by the Dark Lord Morgoth, or turned to evil in the wild. Tolkien's orcs serve as a conveniently wholly evil enemy that could be slaughtered without mercy.
The orc was a sort of "hell-devil" in Old English literature, and the orc-né (pl. orc-néas, "demon-corpses") was a race of corrupted beings and descendants of Cain, alongside the elf, according to the poem Beowulf. Tolkien adopted the term orc from these old attestations, which he professed was a choice made purely for "phonetic suitability" reasons.
Tolkien's concept of orcs has been adapted into the fantasy fiction of other authors, and into games of many different genres such as Dungeons & Dragons, Magic: The Gathering, and Warcraft.