Kasaavin

The Kasaavins are a race beyond N-Space (Normal Space) in a realm that connected to multiple time periods on Earth.

Biology
When manifesting in N-Space, the Kasaavins resemble blinding white humanoids. However this form is an illusion as Kasaavins find the human shape "amusing". Kasaavins could phase through walls, and could temporarily taking the image of that which they had passed through.

Background
In the 21st century, the Kasaavins were manipulated by the Master to take the universe to their realm. This plan was foiled by the Doctor and her allies.

Appearance

 * Doctor Who: Season 12: Spyfall
 * Doctor Who: Season 12: Fugitive of the Judoon