Sentinel
huge beings used to guard the Emperor's palace on Byss, the Sentinels first appeared when the Emperor had hunted down and captured Ashka Boda. In essence, a Sentinel was a former human which had been augmented and enhanced through Sith alchemies, and many were created from tissue stock of other powerful humans. The Sentinels materialized on the battlefield and escorted the fallen Jedi Master to Coruscant. Since then, wild speculation has surrounded the unknown origins of the Sentinels. They are, in fact, clones which have been mutated by the Emperor's Dark Side Adepts. Odd chemicals and the Dark Side of the Force twist the poor beings into slaves that obey the Adepts until they are destroyed.