Homebrew
Your claws are natural weapons, which you can use to make unarmed strikes. If you hit with them, you deal slashing damage equal to 1d6 + your Strength modifier, instead of the bludgeoning damage normal for an unarmed strike.
Your claws are strong enough to burrow into the earth to provide even more protection whether it’s hiding from predators or the harsh beams of the sun. You have a burrowing speed equal to half of your movement speed.
Due to your shell and the shape of your body, you are ill-suited to wearing armor. Your shell provides ample protection, however; it gives you a base AC of 19 (your Dexterity modifier doesn’t affect this number). You gain no benefit from wearing armor, but if you are using a shield, you can apply the shield’s bonus as normal.
You can withdraw into your shell as an action. Until you emerge, you gain a +4 bonus to 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.
Tortisfolk have finely honed survival instincts. You gain proficiency in the Survival skill, as well you become proficient in one of the following skills of your choice: Animal Handling, Medicine, Nature, Perception, or Stealth.