'Rikki-Tikki-Tavi' is a short story in the 1894 anthology The Jungle Book by Rudyard Kipling about the adventures of a valiant young Indian mongoose.
An English family have just moved to a house in India. They find Rikki-Tikki-Tavi the mongoose flooded out of his burrow. A pair of large cobras, Nag and Nagaina, attempt unsuccessfully to kill him. He hears the cobras plotting to kill the father in the house, and attacks Nag in the bathroom. The sound of the fight attracts the father, who shoots Nag. Rikki-Tikki-Tavi destroys Nagaina's eggs and chases her into her 'rat-hole' where he kills her too.