Xanxia

Xanxia was the queen of Zanak. She was practically frozen at extreme age in time dams and watched over by the Pirate Captain.

Biography
At some point, Xanxia created a hologram of herself, pretended to be the Captain's nurse and persuaded him to continually jump Zanak, plundering planets for rare minerals to feed the time dams. She hoped to create a permanently youthful, viable body by preserving her true form in its last few seconds of life, but the Fourth Doctor dismissed this as foolish, stating that there wasn't enough energy in the universe to keep the dams running forever even if she drained the energy from stars, and she would always be dependent on the last few seconds of life in her old body even if the new one became permanent. She was defeated by the Doctor when Zanak was prevented from materialising around Earth. The distraction caused by this failure allowed the time dams and the mountain in which they were enclosed to finally be destroyed by the Mentiads. (DW: The Pirate Planet)