Xanxia

Queen Xanxia was the evil queen of Zanak, she was practically frozen at extreme age in time dams and watched over by the Pirate Captain. At some point she created a hologram of herself, pretending to be the Captain's nurse and persuaded him to continually jump Zanak plundering planets for rare minerals to feed the time dams. Her aim was to create a permanently youthful viable body by permenently preversing her true form in its last few seconds of life, but the Doctor dismissed this as a foolish plan, stating that there wasn't enough energy in the universe to keep the dams running forever even if she tried to drain the energy from stars. She was defeated by the Doctor when Zanak was prevented from materialising around Earth, the distraction caused by this failure allowing the time dams and the mountain they were enclosed within to finally be destroyed by the Mentiads. (DW:The Pirate Planet)