1期13話のウマ娘 キタサンブラック(ウマ娘)?
[tn]"(That) Horse Girl from Season 1 Episode 13"[/tn]

Unnamed anime-only [[Umamusume]] character. Most 'famous' for giving [[Trainer_(umamusume)|Team Spica's Trainer-san]] a kick to the face at the end of Season 1 Episode 13.

[[Horse girl]]. Has [[long hair|long]] [[black hair|black]] (sometimes [[blue hair|bluish-grey]]) hair, with a single [[white hair|white]] forelock. Wears an [[orange bow|orange]] [[ear bow]] on [b]her right ear[/b]. Highly resembles an older version of [[Kitasan Black (umamusume)|]].

Initially speculated to be Kitasan Black (and tagged such on Japanese websites) before the latter made a named appearance in Season 2.
s1e13 umamusume