New Delhi, Oct. 31 -- In Lucknow, Anamika Saini is shaping a pair of pointed ears out of clay. A bone neckpiece, also of clay, sits drying beside them. The 23-year-old optometry student and content creator is crafting a Bengali witch for her Instagram followers; the look will cost her Rs.300-400 and the better part of an evening. "It takes 4-5 hours to create one look, shoot it, remove it and clean up the mess," she says. "After that, I have to bathe."

The witch has a name: the Shakchunni. In Bengali folklore, she is the ghost of a married woman who died before her husband, still in her red-and-white sari, conch-shell bangles and sindoor, forever longing for the life she lost. This October, she is trending on Instagram. "Navratri was on,...