Turtleborn (5e Race Variant)
From D&D Wiki
When you choose a draconic ancestry for your dragonborn character, you can choose to have a dragon turtle ancestry. The ancestors of dragonborn were hatched from eggs laid by a dragon turtle, half buried in the sand. Dragon turtle mothers often do not stay with their eggs, so the progenitors of turtleborn clans may or may not have been shaped by their influence. They have dark green scales, edged with silver. They have an affinity with the ocean, and often become sailors or pirates.
Amphibious. You can breathe air and water.
Breath Weapon. You can use your action to breathe steam in a 15 ft. cone. Each creature in the area of the exhalation must make a Constitution saving throw. The DC for this saving throw equals 8 + your Constitution modifier + your proficiency bonus. A creature takes 2d6 fire damage on a failed save, and half as much on a successful one. Being wet or underwater doesn't grant resistance against this damage and 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.
Damage Resistance. You have resistance to fire damage.
Languages. You can speak, read, and write Common, Draconic and Aquan.