The Shaktisamgama-tantra narrates the birth of Ucchishta-matangini. Once, the god Vishnu and his wife Lakshmi visited Shiva and his second wife Parvati (a reincarnation of Sati) and gave them a banquet of fine foods. While eating, the deities dropped some food on the ground, from which arose a beautiful maiden who asked their left-overs. The four deities granted her their left-overs as prasad, food made sacred by having been first consumed by the deity. This can be interpreted as the Ucchishta of the deity, although due to its negative connotation the word Ucchishta is never explicitly used in connection to Prasad. Shiva decreed that those who repeat her mantra and worship her will have their material desires satisfied and gain control over foes, declaring her the giver of boons. From that day, the maiden was known as Ucchishta-matangini.

Matangi is often described as an outcast and impure. Her association with pollution mainly streams from her relation to outcaste communities, considered to be polluted in Hindu society. These social groups deal in occupations deemed inauspicious and polluted like a collection of waste, meat-processing and working in cremation grounds.

Matangi is regarded as a Tantric form of Saraswati, the goddess of knowledge and the arts of mainstream Hinduism, with whom she shares many traits. Both embody music and are depicted playing the veena. They are also both said to be the Nada (sound or energy) that flows through the Nadi channels in the body through which life force flows. Both are related to rain clouds, thunder, and rivers. Though both govern learning and speech, Saraswati represents the orthodox knowledge of the Brahmins while Matangi—the wild and ecstatic outcast—embodies the “extraordinary” beyond the boundaries of mainstream society, especially inner knowledge.