Thracian
The Thracians are a tribe of Pony physically identical in appearance to Earth Ponies.
History
According to tribe descendant Swift Foot, the Thracians inhabit the island of Thrace, which was discovered by its namesake and their tribe founder King Thrace. As a result of Thrace's supposed rejection by the Founders of Equestria, the Thracians disdain friendship and eventually came to seek to destroy that among the other pony tribes.
Etymology
"Thracian" refers to anything from the land of Thrace, a region that makes up the modern day Balkans of Europe. Interesting, the Arimaspi comes from Scythian folklore, a people group from Thrace.