Amphion and Zethus
In Euripides' lost play "Antiope", Antiope flees back to the cave where she gave birth to Amphion and Zethus; they are now living there as young men. They disbelieve her claim to be their mother and refuse her pleas for sanctuary, but when Dirce comes to find Antiope and orders her to be killed, the twins are convinced by the shepherd who raised them that Antiope is their mother. They kill Dirce by tying her to the horns of a bull.