Talk about it here.
- You may be looking for the Zygon guards from The Zygon Invasion.
Two Zygon guards escorted Kate Stewart, who they believed to be a Zygon, from Truth or Consequences to the Zygon pod chamber. They disguised as UNIT soldiers but, when they encountered Osgood and the Twelfth Doctor, Kate turned on them and shot them. (TV: The Zygon Inversion)