Zr'gn

Zr'gn
The Zr'gn were a race on the planet Zkel (Sleep Dust)

Appearance
The Zr'gn looked like cockroaches, though they had some differences, such as four wings, a humanoid limb-body ratio, and they had eyelids

History
The Zr'gn were at war with The Hu'kn, they created the Sleep Dust, though it rebelled as it was sentient, The Doctor eventually stopped the Sleep Dust.