Tortle

ability score increase: Choose one of: (a) Choose any +2; choose any other +1 (b) Choose any +1; choose any other +1; choose any other +1

age: Young tortles crawl for a few weeks after birth. They reach adult-hood by the age of 15 and live an average of 50 years.

Size: Medium

speed: 30 feet

Languages: Two languages of your choice

race features:
Size. You are Medium or Small. You choose the size when you select this race.
Claws. 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.
Hold Breath. You can hold your breath for up to 1 hour.
Natural Armor. 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.
Nature's Intuition. Thanks to your mystical connection to nature, you gain proficiency with one of the following skills of your choice: Animal Handling, Medicine, Nature, Perception, Stealth, or Survival.
Shell Defense. You can withdraw into your shell as an action. Until you emerge, you gain a +4 bonus to your AC, and you have advantage on Strength and Constitution saving throws. While in your shell, you are prone, your speed is 0 and can't increase, you have disadvantage on Dexterity saving throws, you can't take reactions, and the only action you can take is a bonus action to emerge from your shell.