Hold Breath. The tortle can hold its breath for 1 hour.
Multiattack. The tortle makes four Claw attacks or two Nature's Wrath attacks.
Claw. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 2) slashing damage.
Nature's Wrath. Ranged Spell Attack: +4 to hit, range 90 ft., one target. Hit: 9 (2d6 + 2) damage of a type chosen by the tortle: cold, fire, lightning, or thunder.
Shell Defense. The tortle withdraws into its shell. Until it emerges, it gains a +4 bonus to AC and has advantage on Strength and Constitution saving throws. While in its shell, the tortle is prone, its speed is 0 and can't increase, it has disadvantage on Dexterity saving throws, it can't take reactions, and the only action it can take is a bonus action to emerge.
Spellcasting. The tortle casts one of the following spells, using Wisdom as the spellcasting ability (spell save DC 12):
At will: druidcraft, guidance