Got this idea in my head the other day. How big would a werewolf have to be to accommodate a human's weight? Twice the size? Anatomy wise there are bipedal but are capable of running on all fours.
As for what the werewolf would look like, something like this.
(Artwork done by my friend Entar0178 on Deviantart)
As you can see, a big saddle on its back for the rider, possibly with reins, saddlebags etc, maybe a bit more armor for protection depending on the situation. The werewolf running on all fours would be able transport the rider a great distance, although standing up would probably knock the rider off. Also having a rider on its back would probably hinder its ability to fight.
I dunno, what do you think? Do you think a werewolf mount is practical or not?