[@Muttonhawk] Alright, maybe not hain, but think- [i]Goblins have probably been doing this for centuries.[/i]

Now that I think about it, since they're mountain dwellers, they've probably been doing it with wild sheep and goats to take advantage of their superb footing (especially since goblins are kinda clumsy themselves). Tedar could help breed a particularly reliable goat for the job, and given what rams and billies are like when they're angry, this idea is, somehow, surprisingly badass.

For a legit answer, though, [i]boars.[/i] They're large, fast, tusk-bearing, and probably have the bulk to support a hain. All you'd need is a breed that's actually [i]less[/i] aggressive and temperamental than normal boars on Earth, and you'd have a horrifying war mount.

ed: Boar-riding hain and hellhound-riding hain could specialise for different tasks, or come from different cultures (and then meet on the battlefield).