Okay, in order to get an idea of a species name, I looked at the names of the other races and their origins.
Unicorn-Latin~~”Uni Cornu”~~ One Horn
*Pegasus-Greek~~”Pege”~~ Spring or Well
alternatively, Luwian/Hittite - “Pihassas” - Lightning (liking this one)
*Alicorn- (my interpretation) Latin- “Alae Cornu”- Wings + Horn
*Pony- from Proto Celtic “Epona/Eppos”- Mare/Horse
*Horse-Proto Indo European- “Khers”- To Run
My offerings are- “Crebrum”-from Latin Creperum, meaning Darkness
and “Noctals/Noctales” from Latin Noct (night) and Alae (wing)
Thought of Tenebris (another word for darnkess) or Umbrae (Shadow) but they don’t roll off the tongue as well.
We can just call them bat ponies.