In Greek mythology, which of these is not a god?

Calypso was a nymph in Greek mythology, who lived on the island of Ogygia, where, according to the Odyssey, she detained Odysseus for seven years.

Calypso is generally said to be the daughter of the Titan Atlas and Pleione. Hesiod, and the Homeric Hymn to Demeter, mention either a different Calypso or possibly the same Calypso as one of the Oceanid daughters of Tethys and Oceanus. Apollodorus includes the name Calypso in his list of Nereids, the daughters of Nereus and Doris.

Poseidon was one of the Twelve Olympians in ancient Greek religion and myth, god of the sea, storms, earthquakes and horses. Zeus is the sky and thunder god in ancient Greek religion, who rules as king of the gods of Mount Olympus. Hera is the goddess of women, marriage, family, and childbirth in ancient Greek religion and myth, one of the Twelve Olympians and the sister and wife of Zeus.