The hippocampus is half horse, half fish. It is not to be confused with the tiny “seahorse” known to mundane oceanography. the hippocampus of Greek myth was the mount of Poseidon, god of the Sea, known for their swiftness and power. The sea Merpeople breed these magnificent creatures and so their hair is quite easily found in the magical trade routes of the Mediterranean. The hair has a blue-green light that shines when enchanted into a wand with the luminescence of the sea. It is most suitable for wands that are consecrated to elemental Water and intended for use in the magic of emotions, healing, and female mysteries.
“There [at Taenaros] Neptunus [Poseidon] brings hom to haven his coursers wearied by the Aegean flood; in front their hooves paw the sand, behind, they end in fishy tails beneath the water.” — Thebaid 2.45
“He [Poseidon] towers on high above the peaceful waves, urging his team [of Hippokampoi] with his three-pronged spear: frontwise they run at furious speed amid showers of foam, behind they swim and blot out their footprints with their tails.” — Achilleid 1.25
“Eratosthenes says that he himself saw the place [town of Helike], and that the ferrymen say that there was a bronze Poseidon in the strait, standing erect, holding a Hippokampos in his hand, which was perilous for those who fished with nets.” — Strabo 8.7.2
“[Description of an ancient Greek painting:] Poseidon’s journey over the sea I think you have come upon in Homeros, when he sets forth from Aigai to join the Akhaians, and the sea is calm, escorting him with its sea-horses and its sea-monsters (ketea); for in Homeros they follow Poseidon and fawn upon him as they do here in the painting. There, I imagine, your thought is of dry-land horses — for Homeros maintains that they are ‘bronze-hoofed,’ ‘swiftly-flying,’ and ‘smitten by the lash’ — but here it is Hippokampoi that draw the chariot, creatures with web-footed hoofs, good swimmers, blue-eyed, and, by Zeus, in all respects like dolphins.” — Philostratus the Elder