Callisto was a nymph associated with Artemis, the virgin goddess of the hunt. Callisto attracted the amorous attentions of Zeus, king of the gods. When Artemis discovered Callisto had become pregnant, she drove her out of her band of followers. When it came time for Callisto to give birth, she retired alone to the woods; there she produced twin sons, Arcas and the son of Zeus. According to Hyginus's account in Fabulae: "When Juno noticed that Callisto gave birth to Arcas, son of Jupiter from the nymphs whom Diana associated with, [Juna,] filled with ire, changed Callisto, whom Diana held most cherished, into a bear." Some tell Juno cast off the bear to the stars instead (as the constellation Ursa Major "The Great Bear") along with its cubs which became Arcturus "Bear-Watcher" and the constellation Ursa Minor, "The Little Bear." As an alternative, an alternative account preserved in a scholium on Aratus claims: Callisto herself chose to transform into a bear to escape Juno's wrath: Juno was unable to alter this form back without infringing on Zeus' prerogative so had Zeus place Callisto, and her new bear cubs, among the stars as consolation. It should also be noted that the identity of "her first-born, the son of Zeus' is somewhat vague in this telling (although an Orphic fragment appears to indicate it was named Lycaon). Other variations include a much later Roman mosaic which gives the two bears a single name; Helice. Hyginus, in another account notes Juno turned Lycaon as well as his 49 older brother into wolves with Zeus changing one brother back before Juno noticed. However most familiar versions hold: Juno turned Callisto into the constellation of the Great Bear as punishment while Lycaon went on to try serving Zeus' own infant son to the gods as a test of their omnipotence (this would lead Zeus to destroy humanity in the Great Flood with exception of Deucalion and Pyrrha.