Reflective Carapace. Any time the tarrasque is targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d12. On a 1 to 5, the tarrasque is unaffected. On a 6, the tarrasque is unaffected, and the effect is reflected back at the caster as though it originated from the tarrasque, turning the caster into the target.

Multiattack. The tarrasque can make four attacks: one with its bite, one with its claws, one with its horns, and one with its tail.

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 20 (2d12 + 6) piercing damage. If the target is a creature, it is grappled (escape DC 15). Until this grapple ends, the target is restrained, and the tarrasque can’t bite another target.

Claw. Melee Weapon Attack: +6 to hit, reach 15ft., one target. Hit: 15 (2d8 + 6) slashing damage.

Horns. Melee Weapon Attack: +9 to hit, reach 10ft., one target. Hit: 18 (2d10 + 6) piercing damage.

Tail. Melee Weapon Attack: +9 to hit, reach 20ft., one target. Hit: 13 (2d6 + 6) bludgeoning damage. If the target is a creature, it must succeed on a DC 15 Strength saving throw or be knocked prone.