The Ixtl is a mysterious sapient life form which evolved on the planet Glor in an unknown galaxy, before that world was destroyed by an unspecified cosmic cataclysm. Some Ixtl were then thrown into the void of intergalactic space, where they waited for uncounted eons, surviving on the faint light energy that permeates the cosmos.
They are over three meters tall, red, cylindrical creatures with four legs and four arms terminating on wire-like tendrils. They are capable of moving through space and draining energy from ships, as well as converting electrical energy directly into kinetic energy and vice-versa. Even more astonishingly, they are capable of rearranging their atomic structure, which allows them to pass right through solid surfaces.
The Ixtl are parasitoids: they search for host victims and, using their ability to become intangible, implant eggs directly into their gastrointestinal cavities. The eggs produce a substance which renders the host paralyzed, and the offspring feeds on the host's body after hatching until it is developed enough to sustain itself on pure energy.
At the peak of their civilization, the Ixtls were a mighty race, capable of moving entire solar systems across the galaxies. It has been speculated that the Ixtl Empire may have existed in the universe that predated the current one, and that very few of them survived the current universe's formation, explaining why such a powerful species is now so rare.
- Discord in Scarlet, by A. E. Van Vogt (1939)
- The Voyage of the Space Beagle, by A. E. Van Vogt (1950)
- Barlowe's Guide to Extraterrestrials, by Wayne Barlowe (1979)
- Some people believe the Ixtl may have been the inspiration for the Xenomorph, despite the movie's creators denying that. Apart from the parasitoidic behavior, the two species don't actually share any similarities, as the Ixtl is fully sapient, doesn't operate in hives and doesn't take genetic material from its hosts. The Xenomorph, meanwhile, doesn't share the Ixtl's ability to drain energy from ships or to become intangible.