Within the many multitudes of Astral Seas within the greater ocean of The Medium is a particular, plane filled with stars surrounded by habitable planets. These stars, their planets, and even their inhabitants form a vital part of a life-cycle of enormous entities called stellowyrms. While they are, by rights, a kind of dragon, their amphibian appearance has earned them the affectionate alternative title: axostellos (ah-SHOW-stello/stella).
Axostellos have the following life cycle:
The axostello embryo is born and incubates in a World-egg. The egg incubates in the warmth of the star within its solar system for at least 1 million years before it is ready to hatch. As the embryo grows it gradually consumes the aqua vitae it is born with.
The embryonic axostello, and magical aqua vitae it swims in, is a tempting morsel for the eldritch beings lurking in the Astral Sea. Therefore, the radiance of the Sun is also a defensive measure against the stalking predators. To counter this, Eldritch beings will typically send minor aberrations, beholders, aboleths, and the like, in an attempt to infect the World-egg and hopefully even kill the embryo, and cause the Sun to kick it from the nest.
As a result, World-eggs come with a natural immune system – mortal humanoids. These tenacious creatures come in a variety of species, humans, elves, dwarves, etc, and defend the World-egg from existential threats.
However, like all immune systems on any scale, any number of things can go wrong including having an over-aggressive population of humanoids that end up harming the ecosystem or even the embryo itself.
The thin ecosystem on the surface and in the crust of the World-egg is fed and supported by the aqua-vitae within it, as well as being nourished by the Sun. Unfortunately for the ecosystems and humanoids living on the World-egg, by the time the axostello is ready to hatch and fend for itself, most of the aqua vitae has been consumed, and the surface ecosystem has already suffered a significant decline. Once the larva hatches, the pieces of shell are discarded into cold space, and not even the warmth of the Sun remains to give the remaining people any possibility of eking out a survival.
The axostello, if it has been born with any litter mates (the typical size is 1, although 2 or 3 are known to occur, especially around binary solar systems), it spends another million years in the vicinity of the solar nest. During this time, it filter-feeds on the passing Astral currents and gas clouds, skimming out individual particles of quintessence erupting from Primus far away.
Adolescent axostellos leave the solar nest once the Sun they are born around goes super-nova, lighting up the Astral Sea in a brilliant flash, and causing the Eldritch monsters to recoil. The axostellos ride the solar wave into the depths of the Astral Sea, in search of a school, or more appropriately, a constellation of other axostellos. These roving groups of young axostellos band together for protection against Eldritch predators, and will navigate towards nova to recruit new members, and in search of more bountiful gas clouds. The term constellating refers to the trail of stars left behind by a school of axostello as members court and reproduce.
Nobody knows what courting rituals or customs these being have, what their sexual or reproductive morphology or habits are. It is likely that axostello court in the school, and leave it, once enough gas has been harvested to produce the necessary clutch of eggs.
Once these creatures reach reproductive maturity, they leave the school and are left behind to begin the solitary process of nesting. Filled with astral gasses, the pregnant axostello gives birth to a Sun, and at least one World-egg. Sometimes a pair of axostello nest together to create a binary system. Based on astronomical observations, it appears that Suns come in clusters ranging from one, to several dozen or more. But whether this is the work of one axostello or more, is conjecture. It seems unlikely, given the speed at which the schools appear to move, and the time taken to produce a cluster of eggs, that nesting axostellos ever return to the school once leaving it.
Once nesting is complete, it seems that the axostello, exhausted from the effort of creating at least a few Suns, and without the protection of a school, is unable to defend itself for long from the stalking Eldritch teeth and tentacles. It is likely that its last act is to draw the hungry eyes away from its cluster of Suns and World-eggs by swimming into the deep, un-constellated Astral Sea, offering itself up as an alternative sacrifice. Its flesh is sufficient to at least hold the dumb ravenous attention of those ancient terrors long enough to give the World-eggs time to develop their own defences.