In Greek mythology, the creature born from the blood of the castrated Uranus is the Furies or the Erinyes. According to myth, when Uranus was overthrown by his son, Kronos, his severed genitals fell to the earth, mixing with Gaia and producing the Furies, who are embodiments of vengeance and retribution. The Furies are significant in enforcing moral order and punishing those who commit crimes against the natural and divine laws. Their birth underscores the themes of revenge, justice, and the complex relationships between children and their parents in Greek mythology.