Dragon Tortle

Size: Your size is Medium.   Speed: Your base walking speed is 30 feet, and you have a swim speed equal to your walk speed.   Dragon Affinity: Dragon Tortles have an innate connection to dragon magic. You can choose one of the following damage types: fire, cold, acid, lightning, or poison. You gain resistance to that damage type and this choice determines the appearance of their scales and grants them a corresponding breath weapon. You can replace one of your attacks to exhale destructive energy in a 15-foot cone, the saving throw is 8 + your Constitution modifier + your proficiency bonus. The type of damage and saving throw DC are determined by your chosen draconic heritage:  

• Red (Fire): d10 fire damage, Dexterity saving throw.
• White (Cold): d10 cold damage, Constitution saving throw.
• Black (Acid): d10 acid damage, Dexterity saving throw.
• Blue (Lightning): d10 lightning damage, Dexterity saving throw.
• Purple (Poison): d10 poison damage, Constitution saving throw.

  This damage increases by 1d10 when you reach 5th level (2d10), 11th level (3d10), and 17th level (4d10). You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.   Shell Defense: As a reaction, you can withdraw into your shell, gaining a +2 bonus to AC until the start of your next turn. While in this defensive state, you have resistance to bludgeoning, piercing, and slashing damage.   Natural Armor: Due to your shell and the shape of your body, you are ill-suited to wearing armour. 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 armour, but if you are using a shield, you can apply the shield's bonus as normal.