Telxzana

 was a Pzorswihr. At the time she met the Fifth Doctor and Nyssa, she was the last of her race and was dying.

She inhabited the planet on which Monitoring Base XL-7 was located and tried unsuccessfully to contact Sebastian Musgrove, the only inhabitant of the base, to warn him of her impending death. Once the Doctor and Nyssa arrived, he was able to make contact with Telxzana. The Doctor arranged for Sebastian to leave the planet, but Sebastian stayed with Telxzana until she died. (PROSE: Lonely Days)