Here's my entry for the contest ckutalik put up at Hill Cantons.
Galbaruc, Yash-Kunag, and the Great Culling
Every year, the port town of Galbaruc holds the Feast of the Great Culling, and the town's population swells to over four times its normal size. Innkeepers, hoteliers, and any citizen with so much as a spare broom closet raise their rates to an astonishing degree, but seasoned travelers have learned by now not to haggle, grateful for even the most modest accommodation for the 12 days of the Feast. Galbaruc looks out on the Bay of Maidens, and it is in these waters that Yash-Kunag the Many-Toothed makes her annual trek to birth her young. This enormous, immeasurably ancient sea-creature, whose massive form has never been reliably set down, is worshiped as a goddess by the inhabitants of much of the surrounding coasts.
She is seen as the living embodiment of the sea, in all its bounty, danger, and pitilessness. Local artisans most commonly depict her as a humanoid female, with generously- proportioned hips, pendulous breasts over which hang garlands of seaweed and coral, with a skirt made from the lashed-together bodies of dead men, and topped with a monstrous shark's head.
In all, she will birth many thousands of young over the next ten days, though a tiny fraction of that number survive to adulthood. The larger, faster, and stronger spawn will devour their brothers and sisters in a frenzy of hunger. Others will be picked off, in turn, by other sea creatures, which are always at hand in the waters surrounding the bay to pounce on any godling foolish enough to stray out into the greater depths. The rest are taken in the Great Culling, where mariners, fisherman, and enthusiastic amateurs from every corner of the world converge to hunt this precious bounty. It is believed by the devout, and allowed by the skeptical, that Yash-Kunag herself tacitly approves of the Culling, as a way of weeding out the weak and slow from her progeny, and to reduce the number of rival claimants for her power, which she must battle and devour ever season in turn.
Spawn of Yash-Kunag the Many-Toothed (Stats are for B/X D&D)
Armor Class: 6
Hit Dice: 6
Attacks: Bite/Tail + Special
No. Appearing: 0 (1-8)
Save As: Fighter 6
Treasure Type: Nil
Each Spawn, from birth to the first two weeks of growth, measures some 8-12' in length. Their tails are ridged with long, flexible spines, and their mouths filled with rows of razor-sharp teeth, which are constantly replaced throughout their lifetimes. At this stage, Spawn are creatures of pure instinct, though they will develop a formidable intelligence in later life- cycles. They are drawn to sources of food and devotion. Thanks to their heritage, they have an uncanny ability to inspire religious awe in humanoids. Every two rounds, all humanoids within 20' of a conscious Spawn must Save vs. Spells to avoid being the victim of hold person, unable to do anything save falling to their knees and chanting unintelligible syllables. If removed from the water for more than three rounds, a Spawn will enter a helpless comatose state, losing 1d4 hit dice every subsequent round until death. If returned to the water before death, consciousness returns instantly and it regains hit dice at a rate of 1d8/round. As their natural armor has yet to fully develop, they do take damage from non-magical weapons, but all such damage is halved.
The Spawn of Yash-Kunag the Many-Toothed are highly prized for their carcasses, which have many and varied uses. The meat is tender, rich, and flavorful, and is often grilled or fried in butter and garlic, and sprinkled with salt and herbs. The shimmering, reflective skin, multi-hued like mother-of-pearl, when dried, makes an attractive, water-resistant leather, and some artists and poets attest to the strange, seductive visions half-glimpsed in its surface. Its oil burns brighter and longer than conventional lamp oil, and exudes a pleasing aroma. This oil is also used in cosmetics, and imparts a youthful glow to the skin and a lustrous sheen to the hair. The flexible tail spines find use as surgical tools and writing implements. The teeth are often made into small daggers with delicately serrated edges. These never lose their sharpness. The bones are both strong and flexible, and used in everything from garment foundations to ornaments for the hair. Many of the most daring hairstyles displayed by gentlemen and ladies of fashion in the Northern Cities would be impossible without strategically-placed supports of Spawn-bone.
Spawn-Fishing Boats, and Techniques of Capture
A bewildering array of craft ply the waters of the bay during the Great Culling, from the swift, fragile catamarans of the Broken Knife Islanders to the lateen-sailed dhows of the Western Khanate. The merchant house of Pinfeather and Brassbolt have lately had much success with their unique design, as well as their methods of capture. The ship itself is a two-hulled catamaran, but built significantly larger and higher than those of the Islanders, sacrificing speed for size, cargo-space, and more solid construction. A net is lowered into the sea in the space between the hulls. Designated members of the crew stand near the edge, armed with incense censers, prayer rattles, and flutes, all of which serve to attract Spawn and bring them swimming in the path of the net. When 1-3 spawn are so positioned, the net is hauled up, leaving the spawn struggling in midair and mitigating much of the danger from teeth and tail.
At this point, the Ship's Atheist, recruited for the season from one of the Northern universities, takes position, loudly denouncing as irrational, primitive and servile the worship of large sea-creatures, however impressive in size and power they might be. It is believed that this serves to discourage the Spawn and act as a buffer against its natural powers of instilling awe. This power is justly feared, as it often results in death, failure, and numerous small cults spontaneously developing among fishing crews. Harpoons may also be employed, though this is frowned upon in many modern operations, as they are not always effective, and may damage the skin. Once the Spawn is comatose, it is hauled aboard and flung into special lead-lined compartments built into the side of the ship.