Tersurus
Tersurus was a planet that had singing stones and clone banks. (NA: All-Consuming Fire) Following a ploy with the Daleks on 22nd century Earth, the Master travelled with Susan Foreman in his TARDIS to Tersurus, where she believed she killed him. During the encounter, his TARDIS sent a signal to Gallifrey that brought Chancellor Goth to Tersurus, where he found the Master. (EDA: Legacy of the Daleks, DW: The Deadly Assassin)
In a parallel universe, the Doctor met the Master on Tersurus. According to both the Master and the Doctor, the Tersurons were the most gentle though shunned race in the universe. They communicated through carefully controlled "gastric emissions", and became extinct when they discovered fire. They were referred to as 'the nicest race in the universe, yet simultaneously the most hated and shunned' for this very reason. (DW: The Curse of Fatal Death)
Behind the scenes
It is suggested in The Taking of Planet 5 that the Tersurans actually exist and communicate in the manner described in Curse; during the novel, the Eighth Doctor faces a creature called a Memeovore, a devourer of concept, which is apparently responsible for the Tersurans' unusual means of communication when it deprives them of the concept of other means of expressing themselves.
