Korus was a Human male citizen of the Empress Teta system who served as the royal tutor of Satal and Aleema Keto, heirs to the Tetan throne. Continually berated by the young Ketos, Korus acted as a spy for Satal's father, Lord Keto, secretly reporting on the activities of his son and niece. When Korus' eavesdropping was discovered by Satal and Aleema, who had since formed a Sith cult known as the Krath, they used their newfound dark side powers to make him believe that his tongue was transformed into an Adegan eel.