Kothanodi is based on characters and events described in "Burhi Aair Sadhu", a popular compendium of folk stories compiled by Assamese literary giant Lakshminath Bezbaroa. The four fables referenced in the film are Tejimola, Champawati, Ou Kuwori and Tawoir Xadhu. Once upon a time, Senehi, a schizophrenic woman who loathes her stepdaughter, plots her murder when her husband is called away on a distant trip on business. Her husband, Devinath, encounters a woman called Keteki who has given birth to an outenga, which rolls around after her. Devinath resolves to unearth the mystery of the outenga. Meanwhile, in another village, a rich woman named Dhoneshwari is getting her daughter married to a python - a wedding that has dire consequences for the girl. As these three stories unfold, another mother, Malati, resolves to save her newest born from the clutches of her husband Poonai and his uncle, who have sacrificed all three of her previous babies. In doing so, she unearths a shocking truth.