Story of Demoness Ayomukhi and Lakshman is found in the
Aranya Kanda of Ramayana. Sita is kidnapped and the two brothers start a frantic
search for her. They meet Jatayu who was mortally injured by Ravana. He gives
them the direction in which Ravana carried Sita away.
The brothers were now walking towards South. The passed
through the dense forest
of Dandaka
The demoness was huge in size and fearful to look at. She
approached Lakshman and expressed her desire to marry him.
Lakshman who was tormented by the kidnapping of Sita had no
patience. He took out his sword and severed her nose, ears and breasts.
The Rakshasi ran away from the spot.