Amma Nagamma (2001)

Dr. Amar lives wealthy lifestyle along with his wife, Savitri, and a school-going daughter. He does research work, and is currently involved in studying snakes. One day he ventures deep into a forest and that night witnesses the mating ritual of two shape-changing snakes. He returns back, and shares this incident with his assistant, Buddhu, and friends, Kumar, Guru, and Rakesh. All five of them return to the same spot, and Kumar ends up killing the male serpent, Naag Raj. The female serpent, Naag Devi, swears to avenge the death of her mate and starts on a virtually unstoppable killing spree.