In Chinese Myth, Jiaolong is the aquatic dragon. It is known to take many forms, called chiao. It is sometimes regonized as a man, and sometimes simply a fish. Either way, this dragon was a river dragon, spirtually akin to the crocodile. It is described as 'a snake with four legs'.
They say when a number of fish in a pond reachs 3600, the Jiaolong will come as their leader and enable them to follow him and fly away. This can be stopped, however, by placing a fish trap in the water.