Callisto was a princess or nymph from Arcadia and a companion of the goddess Artemis. After being seduced by Zeus, she bore him a son named Arcas; but she was soon transformed into a bear by either Artemis, Hera, or Zeus. In her new form, Callisto was either shot down by Artemis or made into a constellation.
The nymphs Callisto and Io, for instance, ended up transformed into wild animals as a result of their affairs with Zeus (Callisto into a bear, Io into a cow). [77] In other myths, the nymphs acted as nurses of the Greek gods. Zeus himself was entrusted to nymphs when he was a baby hiding from his murderous (and cannibalistic) father Cronus.
Diana and Callisto by Titian (1556–1559). The National Gallery, London Public Domain