Talk:List of non-pony characters/Seaponies and mermares/@comment-32933435-20181019004147/@comment-29981995-20181019092135

It is a bit of a mess...

Hard to say for certain, given that their depictions vary across the different media. Under the Sparkling Sea depicted real seaponies as basically being large seahorses, while mermares were essentially large fish with the heads of horses. Friendship Ahoy, by contrast, featured Mermares that were closer to what we eventually got in The Movie, with a bit of hippocampus thrown in. The Sirens appear to be more of a full on hippocampus, but obviously with the traditional siren abilities of musically based magic.