Koschei is a character from Slavic folklore, often depicted as an evil sorcerer or immortal being. He is known for his cunning and malevolence, frequently kidnapping princesses and battling heroes. His immortality is tied to a hidden object, usually a needle or an egg, which must be destroyed to defeat him. In many tales, Koschei represents the struggle between good and evil, embodying the fears and challenges faced by heroes. His stories often involve quests, magical creatures, and the triumph of bravery and cleverness over dark forces, making him a fascinating figure in Slavic mythology.