10 Doctor Who Side Characters With Tragic Backstories

Chantho is first introduced in Series 3's Utopia, as an assistant to the kindly old Professor Yana. However, she loses her job in spectacular fashion when Yana - having recently discovered that he's actually the Master - turns on her and kills her.

It's a tragic end to a story that also has a tragic beginning. Chanto is a member of the Malmooth species, humanoid insects that are entirely peaceful, despite their less-than-appealing looks. They lived in a conglomeration on the planet Malcassairo for generation after generation, but at an unknown point in time, this conglomeration was wiped out and the planet became a wasteland, with the hills being roamed by violent humanoids known as the Futurekind.

In the process, Chanto's friends, relatives, and everyone else around her was killed - and she became the last of her species. Based on the Doctor's own experiences, we know how damaging this can be to a person, so all things considered, Chantho actually does a really good job at hiding her grief.

On the plus side, she did ultimately find refuge with Professor Yana inside a human outpost, but once again... that didn't end well.