Johnny Hitchley was a UNIT soldier.
In Turmezistan, he ordered the Zygons hiding out in a church to show themselves. Instead, a Zygon emerged in the form of his mother. Colonel Walsh ordered Hitchley to kill her, but Hitchley instead asked her personal questions, such as his date of birth and favourite teddy bear as a child. However, Zygons disguised as the loved ones of the other soldiers began to emerge, leading Hitchley to bring his soldiers inside. Inside, the Zygons killed them. The Twelfth Doctor and Walsh discovered the ashes that had once been their bodies inside. (TV: The Zygon Invasion)
