In Greek mythology, ichor (Greek ἰχώρ) is the mineral that is the Greek gods' blood, sometimes said to have been present in ambrosia or nectar. When a god was injured and bled, the ichor made his or her blood poisonous to mortals.
Ichor has also been used to mean the blood in a vampire's veins. Whereas many vampire stories and movies describe them as having reddish or dark red blood, others describe vampire blood as being different from human blood altogether—an ichor that is traditionally dark green in color.
The term ichor is often misused in fantasy contexts by authors trying to find a different word for "blood" or "ooze", to the point that it has become cliché. Author Ursula LeGuin, in "From Elfland to Poughkeepsie", calls the term "the infallible touchstone of the seventh-rate."
Ichor has also been used in science fiction as an alien substitute for blood, as in Garth Nix's book Shade's Children. Additionally, in the Dragonriders of Pern novel series, Anne McCaffrey refers to the blood of the alien (but genetically enhanced by humans) Pernese dragons as ichor.
- The Scrin alien race, from Command and Conquer 3, refer to Tiberium as "Ichor", which is a powerful and precious mineral though toxic to humans, much like the Greek mythological mineral.
- Ursula K. LeGuin, "From Elfland to Poughkeepsie", p 80 The Language of the Night ISBN 0-425-05205-2