Place of Origin:
Kristas was a Thal who lived on Skaro centuries after the Neutronic war.
His father died after being crushed by rocks in a landslide. (Doctor Who in an Exciting Adventure with the Daleks)
During the journey to the Dalek City, he stood guard by the Lake of Mutations per Ganatus’s order and later took over leadership through the caverns from Ian Chesterton.
In the Dalek City, Kristas held a closing door up for Barbara Wright, allowing her to get through. He helped fight the Daleks and was shot by one, suffering an injury as a result. Alydon later asked if he was alright and decided to get him up the air. (The Daleks)
After the Daleks’ defeat, Kristas sat next to Salthyana during the feast. He told Ian and Barbara that he planned to propose to her the next day. (Doctor Who in an Exciting Adventure with the Daleks)