I saw that question from the Anon about the horse on the side of the Breyer boxes :3 I wondered that too for a while, until i looked on the bottom of the box. It says something like Horse photo or whatever (c) Bob Langrish. If you look on his site, he has *tons* of equine photos, i'm sure you could find it if you looked :3 I'm just too lazy XD.
I got a few messages about this, so here’s my answer
It is a photo by Bob Langrish, but not one of a famous horse, as far as I can tell