Wikipedia
The Sontarans are a fictional extraterrestrial agendered race of humanoids from the British science fiction television series Doctor Who, and also seen in spin-off series The Sarah Jane Adventures. A warrior race who live to kill, they are characterised by their ruthlessness and fearlessness of death.
They were created by writer Robert Holmes. During rehearsals for their first appearance, actor Kevin Lindsay, who portrayed the original Sontaran, Linx, pronounced the race's name as "son-TAR-an." Alan Bromly, the director, tried to correct him by saying it should be pronounced with the stress on the first syllable. Lindsay declared "Well, I think it's "son-TAR-an", and since I'm from the place, I should know." His preferred pronunciation was retained.