Origin: Buddhist Mythology
Apala's power kept the other evil dragons in check so that the towns around him could prosper. In exchange for their flourishing crops, each family gave Apala a sacrifice to please him. Over time, however, Apala was forgotten and he was angered by this.
He wished to become a poisonous dragon so that he may take revenge. He became the dragon of that country. To this day it is said that all the local princesses in Hindu Kush can control and influence the elements and weather, so long as the local dragon supplies. 
It is said that the renowned sorcerer Gangi is this dragons incarnation. 
Apala was a serpent with two legs and the head of a human.