Your Strength score increases by 1, and your Constitution score increases by 2.

The lifecycle of a turtle dragonborn is similar to their chromatic and metallic cousins. Young turtle dragonborn grow quickly. They walk hours after hatching, attain the size and development of a 10-year-old human child by the age of 3, and reach adulthood by 15. They live to be around 80.

While dragonborn tend to extremes, making a conscious choice for one side or the other in the cosmic war between good and evil, turtle dragonborn are a mixed bag. Some serve as guides and guardians while others fight alongside pillagers and pirates. Some make oaths, other disregard laws. They are a race with their good and their evil.

Turtle dragonborn are smaller than their cousins, but heavier,  averaging almost 400 pounds. Your size is Medium.

Your base walking speed is 30 feet.

When you take the Attack action on your turn, you can replace one of your attacks with an exhalation of blistering steam in a 15-foot cone. Each creature in that area must make a Dexterity saving throw (DC = 8 + your Constitution modifier + your proficiency bonus). On a failed save, the creature takes 1d10 fire damage. On a successful save, it takes half as much damage. This damage increases by 1d10 when you reach 5th level (2d10), 11th level (3d10), and 17th level (4d10).

You can use your Breath Weapon a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Considering your physical form, armor can often be difficult to wear. Your shell serves as your armor and its size and durability offer trustworthy protection. You gain an additional +1 to your Armor Class, but you cannot wear heavy armor.

Your nomadic ways have given you a lifetime of experience. You know the patterns in the wind, the flow of the tides, and the stars above. You know what is edible and harmful in the wilds along the coastline. You gain proficiency with the Nature and Survival skills.

Hailing from the Elemental Plane of Water and familiar with many places under the sea, turtle dragonborn have adapted to even the most extreme ocean depths in a manner similar to tritons. You have resistance to cold damage, and you ignore any of the drawbacks caused by a deep, underwater environment.

Being descended from the mighty dragon turtle, you have a natural familiarity to the sea. You can breath underwater as well as you can on land and have a natural swim speed.

You can speak, read, and write Common, Aquan, and Draconic. Aquan is the language of the elemental plane of water and is shared among the races beneath the tides, many who hire turtle dragonborn as bodyguards and mercenaries against races like sahuagin.