Tortle

Age, Tortles live for around 380-400 years, reaching adulthood around the age of 00.
Size, Tortles stand around 5-7ft tall. Your size is medium.
Speed, your base walking speed is 25 feet and you have a swimming speed 30ft
Hold Breath, you can hold your breath for up to 1 hour at a time.
Natural Armour, 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 17 (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.
Shell Defence, 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.
Snapping Maw, whenever you hit a creature with a melee attack on your turn, as a bonus action you can make a melee attack against the same enemy. If you hit with them, you deal piercing damage equal to 1d8 + your Strength modifier and they must make a STR save (Dc = 8 + Proficiency bonus + Strength modifier) or be grappled. 
Languages, you can speak, read, and write Common and one other language of your choice.