Karkotak / कर्कोटक
Karkotak was a serpent-king, son of Kashyap by his wife Kadru. Once, because he had deceived sage Narad, the latter cursed Karkotak to immobility and said that he would remain here in the forest till he was rescued by King Nal. And there Karkotak remained awaiting Nal. Nal, having lost his kingdom, was forced to retire to the forest. During a forest conflagration, the king heard a voice calling out to him. He walked in the direction of the voice and saw the serpent Karkotak caught in the path of the fire. Karkotak told Nal about his curse. To assist Nal, Karkotak reduced himself to the size of a thumb and Nal then carried him to a safe spot, away from the fire. When Nal had proceeded ten steps, Karkotak bit him and instantly Nal was changed in form. Karkotak, who was again his original self, told Nal that the poison would not harm him, but it was meant to change his form and to torture Kali who had possessed his person. He further advised him to go and take up the job as charioteer to king Rituparn. Nal would later have the opportunity to exchange his knowledge of horses with Rituparn's skill in dice, and then he would meet his wife and children and regain his kingdom. Before he left, the serpent-king handed Nal two garments, which the latter could put on when he wanted to regain his original shape. Karkotak then disappeared.