The traditional Brudvir mount is a Dryas Elk.
A traditional mount for the Brudvir, they are only suitable for temperate to arctic latitudes.
The majestic dryas elk is sturdy enough to act as a mount for a Brudvir, though its temperament is decidedly more ornery than a horse since it is more closely related to goats.
Because of this heritage, they can tread across snowy or steep and rocky terrain with fewer penalties. Well adapted to the northern climates, they can subsist on tougher or more toxic fare such as tree branches and pine needles. However, their thick fur means they are not suited to warmer biomes and will quickly tire or die if not able to regulate their temperature. As such, dryas elk should be kept in temperate, sub-arctic, or arctic biomes.
This uncommon quality mount can help cover long distances more quickly as long as you watch out for pteroguin and are careful not to get whacked in the face with their horns!
A medium-sized animal, a single dryas elk is capable of pulling a medium-weight vehicle such as a wagon or ballista. It can also be ridden by a medium-sized character without special tack. Two animals can be used to pull a vehicle one size larger, or a single animal may pull up to one size smaller.
FWIW, being Brudvir doesn't mean it's not possible to breed horses, but you'll have to obtain them and be in the proper climate to successfully breed them. They may not be native to the Taiga biome, or perhaps only certain breeds are. We'll find out eventually.