The nymph Callisto became the Ursa Major

Callisto is a nymph from Greek mythology who was seduced by Zeus and turned into a bear by Artemis after her pregnancy. Having become a beast, she was almost killed by her own son Arcas during a hunting trip before being saved by the gods. Zeus or Hera then placed her in the sky to form the Ursa Major constellation, while her son became the Ursa Minor.