The Mutos are seen as a separate race from the Thals and the Kaleds, despite the fact that the vast majority of them were born to one of those two races. The Mutos were the early stages of Kaled and Thal mutation – the result of the Neutronic war for supremacy on the planet's surface. More were banished as a result of Davros' experiments on captive Thals and on members of his own race. The result of the scientists' research was often the beginnings of a mutation. Some of Davros' other experiments were discarded into the wastelands, caves and lakes around the Kaled city – hideous, deformed creatures. In addition to causing mutations of some of Skaro's existing fauna, others were brand new species crafted in the Kaled Scientific Bunker.
In the latter century of the war, those of either race who were deemed genetically impure in some manner were thrown out into the wastelands between Thal and Kaled lines. It is uncertain whether any Mutos ventured away from the front lines to try and establish a living elsewhere on Skaro, but given the nature of the planet's scarring by this point it is unlikely that a habitable land would have been found before members of any such party perished.
Mutos were considered acceptable as Slave labour by both of the "pure" races on Skaro. The unfortunates were even considered "a waste of ammunition" if shot – resources on both sides had run low by the end of the war. Despite their mistreatment at the hands of the Thals, the Mutos were happy to work with them against the greater threat presented by the Dalek creations. Several mutos were with the Thal group that entombed the first Daleks in the Scientific Bunker. No doubt some were pleased to see the death of Davros – whose experiments had led to many of them to exile.
