Ahiravan or Mahiravana is a demon, brother or son of Ravana in the Ramayana.
Myth
Ahiravan joins Ravana’s battle against Lord Rama when called and secretly carried away Rama and his brother Lakshmana to the nether-world, and after having consulted his friends, he decided to sacrifice the life of the two divine brothers at the altar of 'Mahamaya' ( the Mother Goddess). Eventually, Hanuman saved their life by killing Ahiravan and his army.