A close relative to the dragon, there is a native Korean mythological creature known as an Imoogi.
By one account, they are hornless creatures resembling dragons who have been cursed and thus were unable to become dragons.
By other accounts, an Imoogi is a proto dragon which must survive one thousand years in order to become a fully fledged dragon.
In either case they are said to be large, benevolent, python like creatures that live in water or caves. Their sighting is associated with good luck.