Manasa is the goddess of naga and fertility. She fulfills the wishes &
protects one against snakebite. Associated with the earth and higher
knowledge, she is worshiped mostly in eastern India. Goddess Manasa was
the daughter of sage Kasyapa and Kadru, the sister of the serpent-king
Sesha. She has the power as well to cure infectious diseases &
shower one with wealth and prosperity. She is ritually worshiped with
sacrifices offered to her during rainy season, since, the snakes are
most active in this season. Sometimes, she is supposed to be a pre-Aryan
goddess. Legend has that Manasa even requested her father, Lord Shiva, to include her in the pantheon, so that she is worshipped by humans. Shiva responded to it that if Chand (of Anga kingdom) agrees to worship her, then her wish would be fulfilled. After a lot of tedious trial, Chand finally agreed to worship her with his left hand. And, thus, Manasa is the only Hindu goddess who till date is worshiped by the left hand.
Manasa Devi's well known temples can be found in Haridwar and Chandigarh.