In the Legends
Some believe that in ancient time when two rishis, Pratyangira and Angiras, were meditating discovered a goddess through a Moola Mantram who was nameless. Later she privileged the rishis by naming herself after them and hence she was called as Sri Maha Pratyangira Devi. In her Potri Malai, she is referred as “Angirasar Prathyangirasar Dyaname Potri”.
As told in Markandeya Purana
In the beginning of the Satya yuga, the Lord Narasimha, an avatar of Vishnu, killed the unruly King Hiranyakashipu by tearing up his body and drinking his blood. Because of the anger in Hiranyakashipu’s body and the malicious effects of human blood, Narasimha was drunk on rage and could not be stopped. To calm him down with the power of compassion, Lord Shiva came down as Sarabeswara, a bird-animal-human hybrid.
Upon seeing this, Lord Narasimha created Ganda-Berunda, a two headed-bird that was Sarabeswara’s opposite. Upon seeing this, Sarabeshwara turned into Bhairava (Shiva’s fierce form) and created Goddesses Pratyangira from his third eye. Pratyangira ate the bird, displaying rage the like of which the gods had never seen before. They praised her as she calmed Narasimha down by sitting on his lap.
Narasimhika is another name of hers. ‘Naran’ means human and ‘Simha’ means lion, so she got named thus as she appears with a lion’s face and a human body. It is believed that when Narashimhika shakes her mane, she shambles the stars in the universe.
In the Ramayana
Tthe Hindu epic Ramayana mentions Sri Maha Pratyangira Devi. To become invincible in war, Indrajit, Ravana’s son, was performing “Nikumbala yaga” (a sacred ritual to worship Pratyangira) while Rama and his soldiers were waging war in Lanka. Lakshmana and Hanuman came down to stop this ritual because they knew if Indrajit completed it, they could not defeat him.