What does everyone think about animal characters?

So I have this role play idea where a herd of horses are trying to find basically the closest thing to paradise a horse can have in the wild. I was going to have unicorns and pegasus, just about any type of horse someone might want to play. The horses would be able to talk to each other, and besides the trying to find this land the story would be wide open. Also,there would be no human characters allowed.

I could substitute the horses for humans. In which case they would have lost their home somehow and are trying to find this certain other place to go live. They might have horse drawn carriages and bull powered wagons, sort of like the pilgrims type thing. It could be a realistic role play like that, or they could be some kind of humanoid monster like vampires (but not vampires because that's been done WAY to much). Driven from their home just trying to seek refuge.

In any case, I like the horse idea the best. But I don't know if other people do... hence the interest check! Thank you so much ^_^