Tssrrn stand slightly shorter than humans, averaging at roughly 5' tall, excluding their twin crest that can be raised and lowered to help regulate their temperature and communicate with each other. Their tails are roughly 70% as long as their total height and taper to an extremely flexible tip that they can use as an extra limb for manipulating simple objects. Tssrrn have long, pointed faces mouths that naturally curve up slightly, giving them an appearance that to many mammalian species looks as though they perpetually have a wry grin.   The parallel crests on their head can be raised or lowered subconsciously and consciously, and the membrane that connects the top of the crest to the back of the skull can change colour to communicate the Tssrrn's emotional state, which can include simple ideas such as agreement, indecision, hunger, and so forth. With practice Tssrrn can exert a significant degree of conscious control over this, and some Tssrrn (such as those with acute hearing loss) may take this a step farther and learn Tssrrn Crest Language (TCF), a full sign language that does not require a free hand in order to speak. Past the crest, two parallel ridges of short spines connected with a thin membrane continue down the back and roughly 7/8 the length of the tail where it ends in a slight fin that aids in swimming.   Tssrrn have sleek, pebbly scales covering most of their bodies and are predominantly blue-ish in colour with bold patterns of red, yellow, black, and/or green. Their fronts are typically a lighter colour with smoother scales and are significantly less patterned than their backs and limbs. Tssrrn base skin colour can range from a dull powder-blue to a rich ocean green, with aquamarine, teal and turquoise being the most common skin tones. Their skin has some limited ability to change colour by varying in intensity, becoming more vibrant or more muted based on a Tssrrn's temperature, emotional state or level of activity. Unlike with their crests, only a very few Tssrrn - nearly all of them monks - can claim the ability to consciously control their skin shade to any significant degree. In addition to their natural skin patterning, in many Tssrrn cultures it is common for most members to have one or more tattoos.   A Tssrrn's hand has three fingers and a thumb with a membrane connecting between the fingers up to the second knuckle to aid in swimming. Their feet are have a semipalmate structure, with three partially-webbed forward-facing toes and a vestigial rear-facing toe similar to a heron or a lapwing.

The Tssrrn physiology is somewhat unique in that under certain situations some members of Tssrrn society may spontaneously undergo a change their physical gender. This typically happens when an individual spends the majority of their time in an environment with a heavy gender imbalance, though it may also be triggered other subtle factors which can include repeated exposure to certain drugs or pheromones, high stress levels, and simple random statistical chance. At any given time, a healthy population of Tssrrn will typically have a ratio of approximately 45% male, 45% female, and 10% 'karaki,' an infertile neither/both state that exists partway in between. Transitioning from one state to another typically takes about a month, and it is rare for a Tssrrn to transition more than once per drach.   This physical trait has led to Tssrrn society being one of the most gender-balanced in terms of division of labour, as most individuals will spontaneously change genders at least once during their lifetime.

Tssrrn shipwrights are considered to be the best in all of Dunia, and their vessels are typically designed for speed and manoeuverability. Tssrrn technologies are often created with the assumption that the user will be able to use their prehensile tail as a 3rd limb for manipulating whatever devices they create. The Tssrrn are responsible for inventing the Dunian equivalents of many extreme and bizarre pastimes, including:

• Bungee jumping
• Hang gliding
• BASE jumping
• Zorbing
• etc

Several thousand years ago, during the First Great Dragon Wars, it is said that a small group of dragons worked together to steal several powerful artifacts from their elders and used them to escape to a new world. Thus did dragons, led by the black-scaled earth dragon later known as Draconis, arrive to the worlds of Dunia. The new world was already populated with intelligent creatures such as humans, dwarves and elves, and it is said that each of the Five First Dragons of Dunia used the power of the artifacts that they brought with them to each create a race of creatures who could serve them and interact with these other creatures on their behalf. It is unknown whether the five races, collectively known as the "Dragonkin," really were created or if they somehow traveled or were summoned from another world or plane of existence, but historians agree that there are no traces of the Dragonkin races in any form that predate the arrival of the dragons to this world. Tsalindar, First of the blue-scaled Storm Dragons, created a race of aquatic reptilian humanoids known as the Tssrrn. The Tssrrn are a tropical race, well adapted to their homelands on the islands and archipelagos of the tropical latitudes, equally at home on land and in the water. During the Last Dragon War, a frightful time when the dragons and their allies fought each other directly in open combat, the Tssrrn were the first to win their full independence from their patron dragons after Tsalindar was slain by Xarka, First of the red-scaled Flame Dragons. In the ensuing power vacuum amongst the Storm Dragons, Skryllex was able to maneuver her way to become the head of the Storm Dragons largely with the widespread support of the Tssrrn and the promise that under her watch they would be free to travel the world as they wished.