Koschei The Deathless is a character from Slavic folklore, often depicted as a powerful and malevolent sorcerer. He is known for his immortality, which he achieves by hiding his soul in a needle, which is then concealed within an egg, located inside a duck, which is inside a hare, that is in an iron chest, buried on a remote island. This complex hiding of his soul makes him nearly impossible to kill. In various tales, Koschei often battles heroes, such as Ivan Tsarevich, and seeks to capture beautiful maidens. His character embodies themes of death, immortality, and the struggle between good and evil, making him a significant figure in Russian and Eastern European mythology.