Mamuny -

The Mamuny do not simply steal children; they swap them. If a mother leaves her newborn unattended, the demon replaces the baby with a .

The screams of the changeling would cause the Mamuna to feel sorry for her own offspring. She would emerge from the swamp to reclaim her child and return the human baby unharmed. Proper Names in Translation - The Official Witcher Wiki mamuny

They dwell in thick wild forests, dark marshes, and desolate swamps. The Mamuny do not simply steal children; they swap them

If a Mamuna successfully swapped a child, Slavic folklore provided a highly specific, ritualistic rescue operation: to a midden or garbage heap. Whip the changeling gently with a birch twig. Pour water over it from a cracked eggshell. Shout the incantation: "Take yours, give mine back!" She would emerge from the swamp to reclaim