The Chaos Witch Quelaag is a character from the video game series Dark Souls. She is a boss enemy found in the Demon Ruins area, known for her spider-like appearance and fiery attacks. Quelaag is the guardian of the Fair Lady, her sister, and is deeply connected to the lore of chaos and the Chaos Flame. Quelaag is notable for her tragic backstory, having been transformed into a half-spider due to her connection with the Chaos and her desire to protect her sister. Players must defeat her to progress in the game, making her a significant figure in the Dark Souls narrative.