Otarii, also called Sky Serpents, are a species of Mystical Creature that once lived on the Agras Plain. They are rare among mystical creatures in that they are partially incorporeal, existing on both the Astral Plain and the physical one. Despite the common name, Otarii are in fact mammals, having fur and nursing their young.
Because of their connection to the astral plain, Otarii float in the air as if it were water. They can touch terrestrial surfaces and be stopped by walls, but they appear to "swim" through the air. Interestingly enough, they appear to be limited by some unknown force, only able to climb to a height of a few thousand feet at most and generally unable to fly much more than one hundred feet off the ground.
Wild Otarii move in heards.
Accounts differ as to whether or not the Otarii could be bread in captivity, but they could certainly be captured and tamed. Their maneuverability and natural flying ability made them attractive as war steeds, however they lacked anywhere convenient to mount a saddle. The Setan Seat was invented as a sort of flying chariot that would trail behind the Otarii in flight. It held one to three combatants, usually archers of grenadiers.