Yup, that’s a real horse.
I mean, that in itself is not new. We seepeople go to the trouble of using real horses all time in cosplay. But this one is actually being seriously ridden around, which is cool; Wander (cosplayer Rebecka H.T, aka Darkesttears) has around ten years experience with horses, so knows what she’s doing.
https://kotaku.com/fire-emblem-cosplay-never-dies-in-battle-ever-1636234284
The photographer for these shots was Jens Lanner. Agro is Cassiopeia.
