TransformingAlchemicals
From Exalted - Unofficial Wiki
Well, if the Alchemicals were created by the solar exalted, it's not unlikely that an exalt would pretty soon realize that a warrior who coudl turn into a horse, or a flying dragon, would be pretty effective-- and certainly a form of transport worthy of the law givers.
However, I'm a bit stuck on the rules mechanics for it. Should we take the Lunar DBT system, and use that and mutation points to model the different forms?