Vulcans = Elves Klingons = Uruk-hai (Orcs) Romulans = Moriquendi (Elves of Darkness / Dark Elves) Ferengi = Goblins Borg = Undead (Nazgûl etc.) LotR: Undead The Nazgûl carry daggers known as Morgul-blades meant to break off in the wound, which can turn the afflicted into a wraith.
The Vorta, before being genetically altered. Memory Alpha: Vorta Ira Behr commented about the Vorta, "The Vorta [. . .] started out as Hobbit-like cute little creatures who were genetically altered and directed to do these horrible things." (Star Trek: Deep Space Nine Companion, pp. 618 & 619)