The story of Ahiravan is mentioned in some regional
versions of Ramayana. It must be noted that Ahiravana is not part of the
original Valmiki Ramayana. In some versions, Ahiravana is the son of Mahiravana.
In other versions Ahiravana is another name of Mahiravana. So there is no
consistency regarding the story of Ahiravana. Hanuman took the Panchamukhi
Hanuman form (five face) to defeat this demon.
Ahiravana Son of Mahiravana
In one legend, Mahiravana had kidnapped Bhagwan Sri Ram and
Lakshman. Hanuman then killed Mahiravana and rescued the brothers. Ahiravana
was still in the womb of his mother. But his mother gave birth to him while his
father was engaged in the battle with Hanuman.
Ahiravana immediately grew up and began fighting Hanuman but
he was killed in the battle.
Ahiravana Son of Ravana
In another legend, Ahiravana was the son of demon king
Ravana. He had no interest in joining the war against Sri Ram. But he was
forced to help Ravana when Indrajit was killed.
He captured Sri Ram and Lakshman and took them to Patala
(the netherworld) with the intention of offering them as sacrifice to Goddess
Kamada Devi.
Hanuman rescues the brothers and kills Ahiravana.
Ahiravan and Mahiravana are brothers
In some stories, Ahiravan and Mahiravana are brothers and
they jointly use magic and sorcery to capture Sri Ram and Lakshman. They are
then defeated and killed by Hanuman.
In some versions of the above story, Ahiravana replaces
Mahiravana or Mayilaravana.