Makara begets Makaradhwaja who was later raised by the Ahiravana, a demon king who ruled Patala who was one of Ravana’s son.
When grew up, Ahiravana, seeing Makaradhwaja's strength and virility, gave him job of guarding the gates of his kingdom.
[1][2][3] When Hanuman took a dip in the waters of the sea (after burning down the whole of Lanka with his inflamed tail), a drop of his sweat fell into the mouth of a mighty Makara.
[1][2][4] According to another, slightly different version, when Hanuman took a dip in the sea, to cool himself after burning Lanka; a drop of his sweat, due to the extreme heat generated in his body due to extreme labor by him, fell into the mouth of a giant fish-eat-reptile like creature, Makara, thus impregnating it.
The Jethwa dynasty of Gujarat, who once ruled major part of Kathiawar and later the princely state of Porbandar, therefore, had the image of Hanuman on their royal flag.