Berchta of the emeraldglade

A famous myth, that plants a seed of fear into all who hear. Most of Whitehearth take part in the making and offering of sponge moss stew, as part of the tradition started by this tale.
  The legend focuses on Berchta, a grotesque hag, who lives in a grotto within the Emeraldglade forest. On the first night of cryos, she travels to cities and gives small magical trinkets to those who leave out a hearty bowl of Sponge moss stew. However, if she finds a house where no offering has been made, she transforms into a hideous demon and rips open the stomachs of the residents of the house. She ravenously consumes the food from each of their stomachs, before magically sewing them back up, leaving no traces of her invasive surgery. Those who awaken after her feasting, feel intense stomach pain for weeks as punishment, and will never make the same mistake.