Question: who are the grey sisters?
Answer: In Greek mythology the Graeae (/ˈɡraɪiː/; English translation: "old women", "grey ones", or "grey witches"; alternatively spelled Graiai (Γραῖαι) and Graiae), also called the Grey Sisters and the Phorcides ("daughters of Phorcys"), were three sisters who shared one eye and one tooth among them.