Chelone

In Greek mythology, Chelone (Greek Χελωνη, Khelônê) was a nymph. She refused to attend or was disrespectful at the marriage of Zeus and Hera, she was disrespectful and Zeus or Hermes changed her into a tortoise, condemning her to eternal silence. (Khelônê means "tortoise" in Greek and the tortoise was a symbol of silence in ancient times.)