Hippocampus

Hippocampi are a flourishing species now in the oceans of the world, though they were originally a magical experiment gone wrong. They are a wonder or a nuisance now, depending on who you ask.

Basic Information

Anatomy

Hippocampi have the head, neck, and forelegs of an equine and the body and tail of a sea mammal. They sometimes have the traits of other fish as well. They usually have the body and tail of a predator - dolphins, seals, orca whales. They are, inconveniently for them, still hooved like a horse.

Genetics and Reproduction

Hippocampi reproduce sexually, and they are mammals who have live births. They always have a single offspring. Their gestation period is about 12 months. Subspecies rarely interbreed, and when they do, it is not uncommon for the mother to reject the offspring. A female will usually have somewhere between 5 or 6 foals over the course of their life.

Growth Rate & Stages

Young hippocampi are called foals. They nurse from their mothers for about 12 months and then begin the weaning process, which usually concludes around 24 months of age, or 4 years. They are physically mature between 4 and 6 years, but not sexually mature until around 15 years.

Dietary Needs and Habits

Hippocampus are omnivores. They are as likely to hunt fish, squid, crustaceans, etc. or to browse on vegetation in shallow waters. More foraging and scavenging is a sign of a healthy adult in a holding period of their life, while more hunting behavior is a sign of a growing youth, mating and gestating adults, and others undergoing periods of change and stress.

Biological Cycle

Hippocampi spend most of their time in the Narrow Sea, but every two years they migrate to the warmest sea on the planet, the Whispering Sea, where pregnant females can foal. Because their gestational period is two years, females in a pod sync up on the same two-year mating cycle, and will choose not to breed at a time that would put them off of the same timing as the other females in the pod.

Behaviour

Hippocampi are an apex predator. Their only predator is the humanoids of the world. As big as they are and spending so much time in the shallows, they get seen a lot. They can be aggressive if they feel threatened. They have been known to skirmish over territory with other sea predators, especially when they have young foals in the group. They are curious but mischievious; they've been known to terrorize and tease boats, but they don't usually harm anyone.

Additional Information

Social Structure

Very social creatures, hippocampi share societal structures with orca whales, who are some of their closest relatives (pre-magic being involved).

The smallest social unit is the matriline, which is a mother and her offspring. On average, these matrilines consist of 3-6 individuals, based on the lifespan, gestation rate, and reproductive rate of the hippocampi. The next unit is the pod, which consists of one to four matrilines. Individuals do not leave the matriline, though a matriline will leave their pod for a week or month at a time and then come back. Pods come together periodically to form communities, especially when a large number of hippocami are looking to breed, to allow males to intermingle with females they are not related to.

Geographic Origin and Distribution

Hippocampi live most of their lives in the Narrow Sea, with pods migrating to the Whispering Sea every two years for females to give birth. Pods without females ready to give birth generally don't follow the migration paths.

Average Intelligence

Like most sea mammals, especially the larger predators, hippocampi are incredibly intelligent. They are perhaps through to have almost humanoid intelligence.

Civilization and Culture

History

Long ago, the infamous magical scientist Mareth Talvayn sought to bridge the divide between land and sea. Fascinated by the elegance of horses and the intelligence of sea mammals, Talvayn envisioned a hybrid species that could thrive in the oceans yet embody the strength and grace of a galloping steed. Using an intricate blend of biomancy, transmutation spells, and experimental rune work, she combined the traits of a sleek dolphin with those of a sturdy horse, creating the hippocampus, a creature of powerful aquatic grace and previously only mythical beauty.
The first hippocampus had the streamlined body of a dolphin, with smooth, glossy skin adapted to the waves, but its forelimbs were still that of a horse. Its dolphin tail enabled it to gracefully navigate the waters. Its head retained equine features—a proud muzzle and flowing mane that shimmered underwater, reminiscent of seaweed. The creature could communicate with clicks and neigh-like whistles, and its intelligence rivaled both its parent species.
Talvayn was entranced, and continued to try different combinations; horses with orcas, seals, belugas. She also experimented with mixing in fish traits in some subspecies. Once perfected, Talvayn released her creations into the oceans, viewing them as a gift to the natural world. She enchanted them with self-sustaining magics to ensure their initial survival and their ability to breed true. Over time, the hippocampi became legendary among sailors, who spoke of herds gliding beneath the waves, leaping into the air with powerful grace. While Dr. Talvayn’s motives were altruistic, her creation sparked fierce debate among scholars—some praising her vision, others questioning the ethics of altering nature in such profound ways. To this day, the hippocampi remain a symbol of both scientific ingenuity and the untamed mystery of the oceans.

Hippocampus

magical equines of the sea

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Origin/Ancestry

Magical

Lifespan

Roughly 100 Years

Conservation Status

Uncommon, Not Endangered

Average Weight

22,000 lbs

Average Length

18-25 feet

Body Tint, Colouring and Marking

Coloration varies depending on subspecies. Hippocampi have the coloring of either their fish or sea mammal parts.

Geographic Distribution

• Narrow Sea
• Whispering Sea

Header image by Ryan Stone on Unsplash.

Subspecies

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Dolphin

Talvayn's first experiment, these are the most common hippocampi. They have horse fronts and the dorsal fin and tail of a common dolphin, and the coloring to match the common dolphin. They are the most curious and gregarious of the hippocampi, and as such the most commonly seen.

Seal

The second experiment was the horse combined with a leopard seal. These were casually aggressive, and kind of stupid, so Talvayn stopped using seals in her experiment. However, the ones she'd already released reproduced cheerfully, and they became known as a complete nuisance - a dangerous one. They are also the smallest of the hippocampi.

Orca Whale

Her third successful try, the orca hippocampi are the smartest - and were her favorite. They tend to reproduce slower than the dolphin subspecies, so there are fewer of them. They also tend to go further into deep water and are seen more by boats and less by people on shore. They are the distinctive black and white of the orca.

Orca + Lionfish

The final subspecies seen in the wild is orca-based but lionfish genetics were added. They have lionfish spines instead of a mane and are inherently poisonous. They are the rarest and most reclusive, and occasionally hunted for their very potent poison. They are colored like lionfish instead of orcas. The orca and lionfish varieties are the only subspecies known to interbreed and accept the offspring into their pods, rather than rejecting them.