The Scarlet Sailor, also known as the ‘Blood Moon’ Sailor, is a massive creature from the planet Geb. With their huge size and flamboyant sails, they are among the most stunning and iconic lifeforms found on the planet.

Description and Anatomy

Sailors belong to the clade Ambulanavidae, part of a larger part of a “phylum” of Endostean “animals” called Pnuematapods which combines a complex calcified vertebrate-like endoskeleton with pressurized jet tubes.

The clade is noted specifically for three adaptations: specialized phagopedes [oars] to eat and manipulate the environment around them, jetopedes [jets] for limited jet propulsion, and pneumatophores as auxiliary lungs [cannons].

These adaptations likely started out similar to the feet of Earth’s starfish but got more chambered, muscular, and pneumatized over millions of years of evolution. Likely, the earliest Pnuematapods resembled a cross between a hagfish and a velvet worm in appearance. The skeleton, jets, and many muscles of Pnuematapods, like all Endosteans, can be traced back to an ancestral muscle-lined hydrostatic skeleton/circulatory system. Today, the Ambulnavids are a highly diverse clade, with members highly specialized in their niches, some having their own hardened internal bones.

As mentioned, the most prominent feature of this creature is its signature sail. It serves both as a socio-sexual display structure and as a means of desperately needed thermoregulation, even with their gigantothermy. Like many large Endosteans, they have bellow-like muscles in their gills for further oxygenation, thermoregulation, and suction feeding. Their giant size is even more astounding due to the fact that they have no hearts. Instead, their entire circulatory system is lined with powerful compressing muscles and cilia to pump “blood” through their body, making every single vein function as a heart.


A Sailor’s body is lined with whiskers, statocysts, and many other forms of mechanoreception, making it one of their best senses along with sight and taste/smell. Like all Endosteans, they have what’s called a turret or tower on their back which works in a way vaguely analogous to the Jacobson’s organ in snakes. With feather-like tongues, whiskers, and cilia, they stick to and funnel in particles to sense. This is hypertrophied in many Endosteans to detect pheromones and function as a sociosexual display structure. It’s called a mast in Ambulanavids. Like most Pnuematapods, they have nautilus-like eyes that are deceptively sensitive and sophisticated allowing not only detailed vision but also color vision, a trait that influenced their flamboyant sails,


Scarlet Sailors occupy the shallow marine waters of their planet. While mistaken as “mega-herbivores”, they in fact are generalists, willing to eat almost any organic material they find.

Due to their size, they require a very high-calorie intake. Fortunately, they have a variety of feeding methods, ensuring their food requirements remain fulfilled year-round.

 Their feeding methods include grazing and browsing “plants” and sessile “animals” (the difference between the two is not as clearly defined on Geb), predating “macro-animals” with their mandibles, catching xenorganisms through tentacles, filter-feeding, and suction feeding.

With their enormous size and appetite combined with their diverse and indiscriminate diet, they are ecosystem engineers, irreversibly destroying and reshaping any environment they choose to enter as they carve vast swaths through coasts and seafloors. Their incredibly destructive feeding habits not only cause mass death, but also a vast bounty for any xenorganism who feeds off of their leftovers, feces, and other waste, ground, and large “vegetation” and “animals” they kick up, and of course, carcasses. That’s not even including the xenorganisms that parasitize them, feeding off of their flesh, fluids, and secretions, as well as the creatures that flock to eat those parasites and symbionts.

Among these include:

The cannon fish is a highly aberrant parasitic pnuematapod that often specializes in nesting in and eating the cannons of large Ambulanavids.

Sailer Feathers are a paraphyletic group of Aborivermins that latch onto various parts of sailors. Since they are sessile filter-feeders, they use sailors to catch a ride and get extra food by exploiting Ambulanavid suction feeding. Some may parasitically leech “blood” and other nutritious fluids via their “roots”. They can specialize in different body parts such as jets, oars, and gills.

The Six-Stripe is a “primitive” Euosteopod Endostean that eats all manner of parasites off of Sailors to the point of following them around constantly.


Like all Ambulanavids, they have highly sensitive eyes and color vision analogous to trichromatic or tetrachromatic vision. Ambulanavids are unusual among Pnuematapods, being simultaneous hermaphrodites. They can also signal to potential mates with obscenely loud blatting, tooting, and rumbling that churns the very earth and water around them. They reproduce by internal fertilization via spermatophores.

Behavior and Intelligence

In addition to display structures, vocalizations, and pheromones, they also have been observed to carve simple crude images by swimming close to the seafloor and drawing them in the ground to mark territory and advertise to potential mates. This behavior was once mistaken for sapient at one point by xenobiologists and the general public, an honor shared with the famous Pictograph Fish. It was later proven to be mostly instinctual, and Ambulanavids were proven to be far less intelligent than previously speculated. However, the subject of a Sailor’s geoglyph likely depends on the environment and wildlife, and making one may require some level of conscious planning. Since some geoglyphs may even mark certain landmarks or territories of large xenorganisms, this may be evidence of long-term memory and abstract thought. Furthermore, they require not only some of the largest eyes in the galaxy but also detailed pattern recognition to identify and judge the geoglyphs of others. Smaller, less destructive Ambulanavids are much more sophisticated and prolific with these glyphs. Scarlet Sailor glyphs seem to be far cruder, little more than scribbles in mud that are usually destroyed or obscured on accident by their own maker. In Scarlet Sailors and other giant Ambulanavids, this behavior is speculated to be vestigial. Giant sailors are also vaguely semi-social compared to more sociable, smaller sailors.

Human Interaction and Cultural Impact

Sailors and other Ambulanavids have had an irreversible change on humans who came to colonize the planet, being among the largest, most beautiful, and charismatic creatures discovered on Geb. They instantly became famous due to their enormous size, similarity in appearance to historical ships, and flamboyant sails. These iconic creatures became symbolic of everything big, new, and exciting. The Scarlet Sailor in particular is famous due to the Blood Moon-like sail and the spiritual associations ascribed to it, heralding spirits from an accumulated afterlife permeating all nature. They are often depicted as the quintessential marine “animals” of Geb and are highly popular both in live tourism and in digital and wetware media.

The beautiful appearance of some Sailors initially gave them a false reputation as gentle giants, despite their dangerous and incredibly destructive feeding habits. Only after endangering and taking the lives of several divers and beachgoers did their reputation shift. Now, they were portrayed as terrifying hyper-violent sea monsters who indiscriminately kill everything in their vicinity, which is also grossly over-exaggerated despite having a little more basis in reality. Unfortunately, this has resulted in their culling along the coasts of south equatorial Geb. After the discovery of geoglyphs, the idea of something so huge and alien having art, sapience, and abstract thought took the general public by storm, which ignited a debate on their continued culling. It is still a popular trope in neuro-narrative media but is now widely known to be discredited, which was heartbreaking to many. About a century ago there were many wild speculations about their sapience, some of the tamer ones included religion, foretelling the future, the arcane, and attempting to communicate with humanity.

This entry was made by community member, Scifi Pug.

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