Ganatus was a companion to Professor Ptolem, and a long time friend. He was part of the Thal research group that helped the Daleks into the effects and cause of the Mutant Phase. After the mutant phase invaded Skaro and the Dalek Emperor forced the Fifth Doctor to return the 22nd century, the Emperor implanted his mind into Ganatus' to make sure Ptolem and the Doctor did their work. This caused a paradox when the emperor, in Ganatus' body, started the chain of events that caused the Mutant Phase in the first place. The Doctor forced him to realise this just in time to change history and avert the Mutant Phase, causing the timeline to be reset. (AUDIO: The Mutant Phase)