Lamont

Sister Lamont was a nurse at an oil rig infirmary. She was abducted by the Zygons and impersonated by one of them. The false Lamont acted as Harry Sullivan's nurse after he was shot and wounded by the false Caber, then took him prisoner aboard the Zygons' ship. She later attacked Sarah Jane Smith and locked her a decompression chamber. This Zygon went to the Fox Inn, killed Angus MacRanald and retrieved their hidden surveillance device. She was shot and injured by UNIT troops but made it back to the ship.

The Doctor found the real Lamont in the Zygon ship, along with the other abducted humans, and helped them escape prior to setting the ship to self-destruct. (DW: Terror of the Zygons)