Coatl Island is the largest of a Hawaiian-sized chain of volcanically active islands between Lados and Pla'thos. The island is dominated by the volcano Lecualico, which last erupted _. Underneath the island, in sea caves, a large site of Hetepkan ruins was discovered by the Coatl tribe. These ruins belonged to those hetepkans which revered Lygoc, and carvings depicting the serpent god only helped to cement the Coatl tribe's faith in their Water Serpent. Hetepkan architecture inspired what the Coatl tribe's architecture looks like today, and this is also where they got the name "Lecualico" for the volcano.
The island is inhabited by the descendants of humans which were washed onto the island, then a smaller-sized solitary island little more than the peak of an underwater volcano, after the destruction of Deeptown as volcanic eruptions, earthquakes, and tsunamis wracked the isles of Pla'thos. The people, known as the Coatl tribe, barely survived in the wake of so many natural disasters, but as months went by the island proved to be fertile, with the help of volcanic soil, and they settled in. The people praised Veloria for carrying them away to safety, and this is how their worship of her water aspect began.
Decades passed, and the birthing pains of a new world were hardly finished. The shifting of plates eventually led to more of Lecualico surfacing, much to the relief of the people who would need the additional land to continue to prosper. But their paradise was nearly taken away from them when they experienced their first eruption of Lecualico. The people pleaded with Veloria to save them, and she did, conjuring a great entity from the ocean to put out the fires and clear away the ashen clouds with great gusts of wind. The people accepted this great Water Serpent as an avatar of Veloria, and devoted their worship to it. From then on a cleric of water was born in every generation who would give the gifts of water to the people, and protect them from the volcano.
Meanwhile, an efreeti who was a noble among his people on the Elemental Plane of Fire was spurned by the goddess, and while she was distracted trying to survive the onslaught of the pantheon by the Enemy, he entered the Prime Material to torment her new favorite flock. The efreeti, Alaz Khan, took up residence inside of Lecualico, and plagued the Coatl tribe from that day forward as the Firebird, requiring tributes of valuables and harvest, and when the people had no valuables left to give, he forced them to sacrifice their water priestess, who must be a virgin, on her eighteenth birthday or he would make the volcano erupt. And the volcano never did erupt.
This tradition of sacrifice continued for centuries until _, when Jeryn Greycloud was shipwrecked on the island after a typhoon two days before the current water priestess, Talia's, eighteenth birthday. Jeryn was attracted to Talia, and when he learned of what she must do, he pleaded with her to allow him to face this "Firebird", whom he believed to be most likely a red dragon due to its love for valuables and virgin girls. But when Alaz Khan learned of Jeryn's presence, and his plan, he caused Lecualico to erupt to punish the people. The people fled the island to the surrounding sandbars, and most survived. But Jeryn was washed away with his ship in a resulting tsunami.
After a year or so, when the lava cooled and became more land, and the jungle regrew, rejuvinated, the people returned to the island, and Talia set out to sacrifice herself to prevent any further eruptions. But when she arrived at the mouth of the volcano, Alaz Khan saw what Jeryn had fallen in love with, and he too was captivated by the water priestess. So rather than let her die in the molten rock which surrounded his plateau inside of the volcano, he took her as his queen and lover.
As a noble efreeti, Alaz Khan offered to grant three of Talia's wishes. Her first and only wish, thus far, was to expand the land of her people. And so Alaz Khan brought more sunken land up from the depths of the ocean, amounting to what the island chain is today.
Alaz Khan no longer requires tribute or sacrifice from the Coatl tribe, and after the last eruption of Lecualico added to and revitalized the land, the people have come to worship the aspects of earth and fire as well. The Water Serpent is now sometimes depicted as having a pair of fiery wings. It is for this reason the people have taken the Coatl name. And it is for that reason that couatls have begun to appear on the islands, where they will be revered and protected.