The sea-horse is an heraldic sea-monster, with the foreparts of a horse and the tail of a fish. Period depictions, from the late 15th Century, may show it with forehooves, or with fins in their place; either form is correct. (The latter is more often found in English emblazons, as with the supporters of the Worshipful Company of Pewterers, 1573 [Bromley & Child 198].) There may also be a webbed dorsal fin; this too is artistic license. The sea-horse is erect by default, as in the illustration.
The modified term “natural sea-horse” refers to the small tropical fish of the Syngnathidae family. At one point, it was sometimes blazoned a “hippocampus”, but that term is no longer used in the Society, as being ambiguous. The natural sea-horse’s naiant posture, erect with the tail curled, is its default.
The Crown Province of Østgardr bears: Argent, a sea-horse erect azure within a laurel wreath vert.
Katharine Ravenshill bears: Sable, a sea-horse Or.
Adriana von Vogelsang bears: Vert, two natural sea-horses addorsed argent.