Turtle Dragonborn

Ability Score Increase.
Increase one score by 2, and another by 1.

Age.
Turtle Dragonborn mature slowly. They take until they're 15 years old for the development of a 10-year-old human child, and reach adulthood by 36. They live to be around 160.

Alignment
Turtle Dragonborn have a tendency towards neutral alignments, due to their draconic parent doing the same.

Size.
Turtle Dragonborn are slightly shorter and heavier than dragonborn, standing around 5'8"-6'2" feet tall and averaging almost 350 pounds. Your size is Medium.

Water Breath.
You can use your action to exhale a 30 ft cone of scalding steam or freezing gale and every target in the area must make a Dexterity saving throw, with a DC of (8 + your Con mod + your prof bonus). A creature takes 2d6 fire/cold damage on a failed save, and half as much damage on a successful one. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level. After you use your breath weapon, you can’t use it again until you complete a short or long rest. Being underwater doesn't grant resistance to this damage.

Shell Scales.
You have an unarmored AC of 12 + your dexterity modifier, due to your shell-like scales.

Hold Breath. You can hold your breath underwater for 8 hours.

Languages
You can speak, read, and write in Common, and your choice between Draconic and Aquan.