Hippocamp

The Hippocampus is a mythological creature shared by Greek, Phoenician, Etruscan, and Roman mythology. The hippocamp is depicted as a sea creature with the upper body of a horse with the lower body of a fish.

Etymology
The term "hippocamp" originally derives from the Greek hippokampos (ἱππόκαμπος), which is a compound word comprised of the Greek words hippos (ἵππος), which means "horse," and kampos (κάμπος), which means "sea monster. " From the original Greek, hippokampos latinized as hippocampus (HIPPOCAMPVS), which in turn was anglicized as "hippocamp," though, the latinized version of the name is arguably more common in the anglophone world.

Phoenician and Lydian
Coins minted at Tyre around the 4th century BC show the patron god Melqart riding on a winged hippocampus and accompanied by dolphins. Coins of the same period from Byblos show a hippocampus diving under a galley.

A gold sea-horse was discovered in a hoard from the kingdom of Lydia in Asia minor, dating to the 6th century BC.

Greek and Roman
In the Iliad, Homer describes Poseidon, who was god of horses (Poseidon Hippios), earthquakes, and the sea, drawn by "brazen-hoofed" horses over the sea's surface, and Apollonius of Rhodes, being consciously archaic in Argonautica, describes the horse of Poseidon emerging from the sea and galloping away across the Libyan sands. This compares to the specifically "two-hoofed" hippocampi of Gaius Valerius Flaccus in his Argonautica: "Orionwhen grasping his father’s reins heaves the sea with the snorting of his two-hooved horses." In Hellenistic and Roman imagery, however, Poseidon (or Roman Neptune) often drives a sea-chariot drawn by hippocampi. Thus hippocampi sport with this god in both ancient depictions and much more modern ones, such as in the waters of the 18th-century Trevi Fountain in Rome surveyed by Neptune from his niche above.

The appearance of hippocampi in both freshwater and saltwater is counter-intuitive to a modern audience, though not to an ancient one. The Greek picture of the natural hydrological cycle did not take into account the condensation of atmospheric water as rain to replenish the water table, but imagined the waters of the sea oozing back landwards through vast underground caverns and aquifers, rising replenished and freshened in springs.

Thus it was natural for a temple at Helike in the coastal plain of Achaea to be dedicated to Poseidon Helikonios, (the Poseidon of Helicon), the sacred spring of Boeotian Helikon. When an earthquake suddenly submerged the city, the temple's bronze Poseidon accompanied by hippocampi continued to snag fishermens' nets. Likewise, the hippocampus was considered an appropriate decoration for mosaics in Roman thermae or public baths, as at Aquae Sulis modern day Bath in Britannia (illustration, below).

Poseidon's horses, which were included in the elaborate sculptural program of gilt-bronze and ivory, added by a Roman client to the temple of Poseidon at Corinth, are likely to have been hippocampi; the Romanised Greek Pausanias described the rich ensemble in the later 2nd century AD (Geography of Greece ii.1.7-.8):

Etruscan
Hippocampi appear with the first Oriental-phase of Etruscan civilization: they remain a theme in Etruscan tomb wall-paintings and reliefs, where they are sometimes provided with wings, as they are in the Trevi fountain. Katharine Shepard found in the theme an Etruscan belief in a sea-voyage to the other world.

Pictish
The sea-horse also appears in Pictish stone carvings in Scotland. The symbolism of the carving (also known as "Pictish Beast") is unknown. Although similar but not identical to Roman sea-horse images, it is unclear whether this depiction originates from images brought over by the Romans, or had a place in earlier Pictish mythology.

Medieval and Renaissance, and Modern
The mythic hippocampus has been used as a heraldic charge, particularly since the Renaissance, most often in the armorial bearings of people and places with maritime associations. However, in a blazon, the terms hippocamp and hippocampus now refer to the real animal called a seahorse, and the terms seahorse and sea-horse refer to the mythological creature. The above-mentioned fish hybrids are seen less frequently.

The sea-horse is also a common image in Renaissance and post-renaissance art, for example, in the Trevi fountain, dating to 1732.

A winged hippocampus has been used as a symbol for Air France since its establishment in 1933 (inherited from its predecessor Air Orient); it appears today on the engine nacelles of Air France aircraft.

Bronze hippocampoi appear in Dublin, Leinster, Ireland on lampposts next to a statue of Henry Grattan and on Grattan Bridge.

Capricornus and related mythical animals
Closely related to the hippocampus is the "sea goat", represented by Capricorn, a mythical creature with the front half of a goat and the rear half of a fish. Canonical figures, most of which were not themselves cult images, and coins of the Carian goddess associated with Aphrodite as the Aphrodite of Aphrodisias through interpretatio graeca, show the goddess riding on a sea-goat.

Aside from aigikampoi, the fish-tailed goats representing Capricorn, other fish-tailed animals rarely appeared in Greek art, but are more characteristic of the Etruscans. These include leokampoi (fish-tailed lions), taurokampoi (fish-tailed bulls) or pardalokampoi (fish-tailed leopards).

Modern depictions
As seen in the 2018 Aquaman are seen as steeds for the Atlantians of Xenobyl where Mera's father ruled and uses them similar to Poseidon or Triton did in the Little Mermaid franchise.