A creature that is characteristic of wildlife in Sri Lanka, it also plays a part in legend. This is an original version from the Panchatantra in Sanskrit (translation from Ryder 1925) according to Wikipedia:
"The Loyal Mongoose
There was once a Brahman named Godly [orig. Devasharma] in a certain town. His wife mothered a single son and a mongoose. And as she loved little ones, she cared for the mongoose also like a son, giving him milk from her breast, and salves, and baths, and so on. But she did not trust him, for she thought: “A mongoose is a nasty kind of creature. He might hurt my boy.” [...]
One day she tucked her son in bed, took a waterjar, and said to her husband: “Now, Professor, I am going for water. You must protect the boy from the mongoose.” But when she was gone, the Brahman went off somewhere himself to beg food, leaving the house empty.
While he was gone, a black snake issued from his hole and, as fate would have it, crawled toward the baby’s cradle. But the mongoose, feeling him to be a natural enemy, and fearing for the life of his baby brother, fell upon the vicious serpent halfway, joined battle with him, tore him to bits, and tossed the pieces far and wide. Then, delighted with his own heroism, he ran, blood trickling from his mouth, to meet the mother; for he wished to show what he had done.
But when the mother saw him coming, saw his bloody mouth and his excitement, she feared that the villain must have eaten her baby boy, and without thinking twice, she angrily dropped the water-jar upon him, which killed him the moment that it struck. There she left him without a second thought, and hurried home, where she found the baby safe and sound, and near the cradle a great black snake, torn to bits. Then, overwhelmed with sorrow because she had thoughtlessly killed her benefactor, her son, she beat her head and breast."
Happily, despite the ongoing construction work, the pair remains sighted in and around the estate.