Zygon Kate Stewart

An unnamed Zygon was part of the group stuck on Earth. Their ship landed in 1562, but the group retreated into a statis chamber and stayed there until 2013, where this Zygon took Kate Stewart's form.

In the Under-Gallery, the Zygon attacked Clara Oswald, but fell back when the latter got hold of a vortex manipulator. Later, three of the Doctors erased the memories of both the humans and their Zygon counterparts, and peace was restored. (TV: The Day of the Doctor)