The Xhosa were a group of people who were at war with the Cyrene for centuries. Viktor was a bio-mechanical construct created by them. The Cyrene and the Xhosa later reached an accord. (COMIC: Universal Monsters)
A television broadcast of a smiling Xhosa woman was one the channels which was intercepted, and played briefly on the Eighth Doctor's TARDIS scanner. (PROSE: The Dying Days)
Behind the scenes
The Xhosa are a real-world human ethnic group on Earth. Universal Monsters does not go into any real detail as to whether the Xhosa mentioned in the story are the human subgroup or an alien species with the same name.