IRIS, in Greek mythology, daughter of Thaumas and the ocean nymph Electra (according to Hesiod), the personification of the rainbow and messenger of the gods; as a messenger of the gods, she is mentioned frequently in the Iliad, but never in the Odyssey, where Hermes takes her place. She is in Homer the messenger of both Zeus and Hera, but later the especial servant of Hera. By command of Zeus she carries in a ewer water from
the Styx, with which she puts to sleep all gods who perjure them selves. Her attributes are the caduceus (herald's staff) and a vase.