I'm trying to write a Star Wars story in which Terminus attacks a planet that I've made up and I need to know what kind of beings live on the planet. Terminus is an Outer-Rim planet.
This is what I have found.
It was a heavily trafficked shipping center at the edge of the galaxy, not far from the Red Nebula. It sat at the intersection of the Corellian Trade Spine and Hydian Way. The skies of Terminus were filled with bizarre ships hailing from Wild Space and the Unknown Regions.
Terminus' name and its position as a crucial socioeconomic center at the edge of the galaxy strongly suggest that it is a reference to the planet of the same name that gave rise to a renewed galaxy-spanning empire in Isaac Asimov's Foundation novel series. Furthermore, Asimov's city-planet and one-time galactic capital of Trantor was a partial inspiration for Coruscant.
It appears to be merely a tribute to Isaac Asimov's Foundation series, so I'd be surprised if there was a particularly well developed background story for this planet.
As a side note, I don't think it is a very good idea to write a Star Wars story featuring a planet which was already imported from another universe, especially if you do not intend to write a crossover. But that's just my own opinion.