Dragon Tortles start being able to walk early on at the age of three but they remain tiny for decades. They attain the size and development of a human adult by the time they are 100. They live to be around 400 and never stop growing in size till they die.

You are a Humanoid.

Dragon Tortles are taller and heavier than humans, standing well over 6 feet tall and averaging almost 250 pounds. Your size is Medium.

Your walking speed is 30 feet, and you have a swimming speed equal to your walking speed.

You have claws that you can use to make unarmed strikes. When you hit with them, the strike deals 1d6 + your Strength modifier slashing damage, instead of the bludgeoning damage normal for an unarmed strike.

You can hold your breath for up to 1 hour.

Your shell provides you a base AC of 17 (your Dexterity modifier doesn’t affect this number). You can’t wear light, medium, or heavy armor, but if you are using a shield, you can apply the shield’s bonus as normal.

When you take the Attack action on your turn, you can replace one of your attacks with an exhalation of scalding steam in a 15-foot cone. Each creature in that area must make a Constitution 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 Steam Breath a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.