Thijarian

The Thijarians were an ancient species from the planet Thijar. They evolved themselves to become the perfect assassins.

After their planet was destroyed, and the Thijarians were unable to grieve or honour those they had lost, they left behind their old ways. The Thijarians' new objective was to bear witness, across time and space, to those who had perished. They sought to honour those who would otherwise have died alone.

They carried the remains of their planet and its people inside their hive.

The Thirteenth Doctor, Graham, Ryan and Yaz encountered them whilst travelling to India in 1947, where the Thijarians were waiting to witness the many casualties from the Partition of India. The Doctor was not aware that their planet had been destroyed, or that they were no longer assassins. She had only heard of the Thijarians before this encounter. (TV: Demons of the Punjab)