Hanuman’s Son Makar Dhwaja was born to a mighty fish of the same name when Hanuman after burning the entire Lanka with his tail had dipped in the sea to cool off his body. It is said that his sweat was swallowed by the fish and thus was Makar Dhwaja conceived. The fish was caught by Ravana’s step brother Ahiravana who ruled Patal, the nether world. When Makar Dhwaja grew up, Ahiravana was impressed by his strength and virility. He then made him his soldier.