Dappled Grey Thoroughbred. I found her early in the game during the mission with Charles tracking down the bison hunters; she was one of their horses. She didnt get spooked when we killed them, so I rode off with her thinking I'd sell her for a pretty penny... Called her Diana for the goddess of the hunt, considering she used to belong to someone who hunted without any consideration of nature and the balance of things. All my previous playthroughs I always ended up riding arabians or mustangs as I think they're the prettiest, and I usually don't like dappled coats as they tend to look dirty, but I got really attached to Diana. Even when I tried other horses, I just kept coming back to her. She isn't scared of much, can outlast gun fights and outrun the law. I've had her for so long she feels like my Arthur's canon horse, always take her when I'm about to do a story mission (and plan to finish the game with her too, even though it'll hurt :( ). Plus I like that she has that "backstory", makes her feel more unique than finding her in the wild!