Mother was a member of the Spider Family. Like most demons, Mother was cruel, unfeeling, and murderous towards humans. She ruthless controlled dozens of Demon Slayers through her threads and manipulated them into killing each other. She was also rather sadistic and callous, uncaring that her manipulation brought them prolonged suffering. In spite of this, spending time with Rui's family caused her developed an intense fear for him and Father, both of whom had abused her for being weak.