Hold Breath. The tortle can hold its breath for 1 hour.

Claw. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit:4 (1d4 + 2) slashing damage.

Spear. Melee or Ranged Weapon Attack: +4 to hit, reach 5 ft. or range 20/60 ft., one target. Hit:5 (1d6 + 2) piercing damage, or 6 (1d8 + 2) piercing damage if used with two hands in melee.

Light Crossbow. Ranged Weapon Attack: +2 to hit, range 80/320 ft., one target. Hit:4 (1d8) piercing damage.

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.