Morpheus

In Ovid's Metamorphoses he is the son of Somnus (Sleep, the Roman counterpart of Hypnos) and appears in dreams in human form.

In Ovid's account, Juno (via the messenger goddess Iris) sends Morpheus to appear to Alcyone in a dream, as her husband Ceyx, to tell her of his death.

[4] His name derives from the Greek word for form (μορφή), and his function was apparently to appear in dreams in human guise.

One called Icelos ('Like'), by the gods, but Phobetor ('Frightener') by men, "takes the form of beast or bird or the long serpent", and Phantasos ('Fantasy'), who "puts on deceptive shapes of earth, rocks, water, trees, all lifeless things".

[10] However, Griffin suggests that this division of dream forms between Morpheus and his brothers, possibly including their names, may have been of Hellenistic origin.