Thijarians are an ancient species that were once known to be the deadliest assassins in the universe. They have multiple eyes, fangs, can communicate telepathically and can use transmat tech to teleport.
When Doctor and her friends travelled back in time to India, 1947 to meet Yaz’s grandmother when she was younger, they discovered that the Thijarians (or ‘demons’ as the Punjabi people called them) had been haunting the region.
On further investigation, the creatures revealed that they no longer kill. In fact, they were survivors of the destruction of their civilisation. Their home and people were gone but they weren’t there to grieve and honour them.
So instead of killing, these Thijarians had a new vocation; they watched over the victims of those fighting and bore witness to those who died alone. They were present at the Partition of India in 1947 where more than a million people died, but thanks to the Thijarians, nobody died unmourned.