Satarran

The Satarrans are a sapient, spacefaring species which have been at war against the Lysians for many decades, as of 2368.

Biology
Satarrans are humanoids with a dark skeletal appearance. They're strong enough to take down Klingons and seem to be extremely resistant to phaser fire.

Culture and society
Like their Lysian enemies, the Satarrans are no match for the Federation in terms of defensive systems and weaponry. Both the Satarrans and the Lysians are evenly matched against each other, contributing to their war's longevity.

Despite being far behind the Federation in terms of combat technology, the Satarrans seem to be far ahead in other fields, as they have successfully developed the means to access and alter computer data from Federation ships, even penetrating shields, as well as erase the memories of other species. They're also capable of convincingly disguising themselves as Humans.

According to Prof. Galen, the Satarrans of Sothis III "disdained" mysteries. His use of past tense, coupled with Galen being an archaeologist, suggests that this might refer to an ancient Satarran culture, rather than their current one. Alternatively, it could mean that the Satarrans no longer inhabit Sothis III, which may or may not be their homeworld.

History
In 2368, a Satarran ship successfully erased the memories of the crew of the USS Enterprise-D, as well as altering the ship's computer files. A Satarran operative disguised as a Human named Kieran MacDuff posed as the ship's first officer. The information planted on their computer systems convinced the amnesic crew that they were at war against the Lysians, who were allegedly responsible for the attack that erased their memories, and that their current mission was to secretly infiltrate Lysian territory and destroy their Central Command. Fortunately, the crew noticed the incongruity of being at war against an enemy that seemed so easily outmatched in combat, and exposed MacDuff when the latter desperately tried to take over the ship and complete his mission.

Appearances

 * Star Trek: The Next Generation
 * s05e14, "Conundrum" (1992)
 * s06e20, "The Chase" (1993)