In Greek mythology, Amalthea or Amaltheia (Greek: Ἀμάλθεια) is the most often mentioned among foster-mothers of Zeus. Her name in Greek ("tender goddess") is clearly an epithet, signifying the presence of an earlier nurturing goddess, whom the Hellenes, whose myths we know, knew to be located in Crete, where Minoans may have called her a version of "Dikte". Amalthea is sometimes represented as the goat who suckled the infant-god in a cave in Cretan Mount Aigaion ("Goat Mountain"), sometimes as a goat-tending nymph of uncertain parentage (the daughter of Oceanus, Haemonius, Olenos, or - according to Lactantius — Melisseus), who brought him up on the milk of her goat. Having multiple and uncertain mythological parents, indicates wide worship of a deity in many cultures having varying local traditions. Amalthea becomes blurred with Adamanthea at times and in one tradition, Cronus swallowed all of his children immediately after birth. The mother goddess Rhea, Zeus' mother deceived her brother consort Cronus by giving him a stone wrapped to look like a baby instead of Zeus. Since she instead gave the infant Zeus to Adamanthea to nurse in a cave on a mountain in Crete, it is clear that Adamanthea is a doublet of Amalthea. In many literary references, the Greek tradition relates that in order that Cronus should not hear the wailing of the infant, Amalthea gathered about the cave the Kuretes or the Korybantes to dance, shout, and clash their spears against their shields.
Alternatively, the sacred goat having broken off one of her horns, Amalthea filled it with flowers and fruits and presented it to Zeus, who placed it together with the goat amongst the stars.
According to another story, Zeus himself broke off her horn and, in an example of mythic inversion, gave it to Amalthea, promising that it would supply whatever she desired in abundance. When her horn broke off, leaving her with 1 horn, she changed, and became a unicorn. The goat-nymph, however, was older than the Olympian. Amalthea was a goddess who traditionally provided plenty as part of her nature before the cult of Zeus existed. Amalthea, in this tradition, gave her horn to the river-god Achelous (her reputed brother), who exchanged it for his own horn, which had been broken off in his contest with Heracles for the possession of Deianeira. According to ancient mythology, the owners of her horn were many and various as one tradition was integrated into another. Speaking generally, Amalthea's horn was regarded as the symbol of inexhaustible riches, the horn of plenty or Cornucopia, and became adopted as the attribute of various divinities— of Gaia, Demeter, Cybele, of Hades in his manifestation as Plouton, the bringer of wealth, and of rivers as fertilizers of the land.
The term horn of Amalthea is applied to any especially fertile district. An estate belonging to Titus Pomponius Atticus was called Amaltheum. Cretan coins represent the infant Zeus being suckled by the goat Amalthea; other Greek coins exhibit him suspended from her teats or carried in the arms of the nymph.
Parmeniscus says that a certain Melisseus was king in Crete, and to his daughters Jove was brought to nurse. Since they did not have milk, they furnished him a she-goat, Amalthea by name, who is said to have reared him. She often bore twin kids, and at the very time that Jove was brought to her to nurse, had borne a pair. And so because of the kindness of the mother, the kids, too were placed among the constellations. Cleostratus of Tenedos is said to have first pointed out these kids among the stars.
But Musaeus says Jove was nursed by Themis and the nymph Amalthea, to whom he was given by Ops, his mother. Now Amalthea had as a pet a certain goat which is said to have nursed Jove.