Olympus Beasts of Olympus 6: Zeus's Eagle
Eagle is the only one who can soothe the three-tongued serpent who guards the spring of eternal youth at the source of the River Styx - and Psyche needs 'just a little jug' of water from it to erase Aphrodite's (non-existent) wrinkles and win the chance of marrying her son, Eros.