Trion (The Outer Limits)

The Trions were a primitive race of sentients from the planet Trion.

Biology
The Trions were humanoids, with five fingers and opposable thumbs. Despite their advanced bipedal form, the Trion's brain is around the size of an apple, the cerebral cortex is smooth which is strange as it suggests that their brains developed have yet to pass the evolutionary level of a housecat. Their blood is rich in copper, making their bodies highly conductive of electricity. They are carriers of a strange bio-electric virus that is transmitted through electronics. The virus is deadly to humans, causing heighten paranoid, mental degradation, and suicide.

History
Mankind had since developed technology to traverse the stars, unfortunately humanity facing an overcrowding planet and a belief in a manifest destiny to rule over all worlds, sent forth warships to pacify other worlds. Under guise of destroying aggressive native fauna, these ships dropped payloads of neutron bombs over the worlds leaving them empty for colonization. The civilian populace was unaware of these atrocities by the military. Countless sentient races were killed by these merciless conquerors, until humanity set their eyes on the planet Trion. The planet Trion was home to an alien race at the stage equivalent to early man, the UFS Rhesos was dispatched to clear the world for colonization. After dropping and committing genocide, the crew of the UFS Rhesos, proud of their slaughter, claimed several Trion bodies as trophies.

Shortly later the Earth lost communications with the battleship, resulting in UFS Mercury being sent to learn what had transpired. The only survivor of the battleship was the captain who suffered mental degradation and paranoia, killing his entire crew. The crew of the UFS Mercury soon were afflicted with the same infection brought by the alien corpses that were on the UFS Rhesos.

The virus is later transmitted electronically back to Earth where it will undoubtedly infected the rest of humanity.

Culture
Nothing is known about the Trion but according to Dr. Will Olsten, they were possibly at the stage of early man.

Source

 * Outer Limits: Season 6: Episode 4: Manifest Destiny