You gain a climbing speed equal to its walking speed. You gain advantage on Dexterity Saving Throws when on Difficult Terrain that is wet. You can also move up, down, and across vertical surfaces and upside down along ceilings, while leaving your hands free. Additionally, although you cannot swim, you can traverse underwater surfaces without hindrance.

You can withdraw into your shell as an action. You gain a +4 bonus to AC until you emerge. Here you have an advantage on Constitution saving throws. You are prone while you are in your shell. Your speed is 0 and it can’t increase. You have disadvantage on Dexterity saving throws. You cannot take and action, the only action you can take is a bonus action to emerge from the shell.

You are ill-suited to wearing armour due to the shape of your body and shell. Your shell provides ample protection and it gives you a base AC of 16. You cannot gain any benefit from wearing armour. You can apply a shield’s bonus if you are using a shield.

Snailkin can hold their breath for up to 1 hour. They are not natural swimmers but they can remain underwater for some time before needing to come up for air.