Amber: Something Wicked
Oversized Immortal horses (who can probably shapeshift at least a little), descended of Frostmane, who acted as mounts of the Gods in the old order. They are very strong, very quick and can run on air — and have some degree of air-elemental powers. Some of them know a few spells.
They will bargain services to Makers in general, or bear them for free if there’s something interesting afoot.