Sarosians are a race of creatures who dwell on the dark side of the world and in Rohbredden. They are first mentioned by Queen Chrysalis in Urohringr, ch. 87; the first one we meet is Echo in Ynanhluutr. On the dark side, they are one of the factions involved in the Trinary War. Celestia also mentions Luna employing her own "Sarosian agents".
Following the Lunar War between the alicorns of Equestria, Luna blessed the Sarosians with "...the same power that she used to curse her and her sister's kingdom" When she was banished to the moon, almost all of them fled east in an attempt to cross to the Dark Side and seek communion with their lost Goddess. Those who stayed on the light side congregated in a floating city called Bleak's Plummet, near the very eastern edge, until the events of Utaan.
Their appearance is based on Princess Luna's chariot escorts from the episode "Nightmare Night". These ponies have also been called "Night ponies", "Thestrals", or "Batponies". They have fluffy, leaf-shaped ears. Their skin can burn in direct sunlight without appropriate protection. They can emit piercing shrieks which can deafen and stun nearby ponies.
They have brought many enchanted moon rocks with them from their original exodus at Nightmare Moon's banishment, and have mastered the art of controlling the enchantments to achieve various effects.
- ↑ Utaan, "A World That's Worth Protecting"