Atha Prime

Atha Prime was a "genetics master" and ruler of the dark worlds. He was long exiled to a remote part of the Galaxy but was eventually freed by the death of Emperor Palpatine. While there, he developed elite shock troopers known as Clone Warriors which he used to decimate several Rebel outposts in an attempt to crush the Rebel Alliance. He performed these attacks from his mobile base, the Annihilator, which resembled two Star Destroyers joined together. Prime's personal starfighter, the Apex Invader, was able to attach atop the Annihilator which gave him the ultimate command vantage point for battles, as well as a personal fighting vehicle which was piloted by his droid Blue-Four who was also Prime's personal attendant and confidant.

Behind the scenes

 * Although Atha Prime was originally designed to be a new villain after the death of Palpatine by Kenner, Abel G. Peña later attempted to reuse the character as part of Grand Moff Tractha's betrayal against the Empire. He wrote the character as part of an article for The Official Star Wars Fact Files, but the mention to Atha Prime was never printed.
 * Atha Prime's look was later reused for the Imperial Sentinals.