Multiattack

The titanoboa makes one bite attack and one constrict attack.

Bite

Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 8) piercing damage. If the target is a Huge or smaller creature, it must succeed on a DC 18 Dexterity saving throw or be swallowed by the titanoboa. A swallowed creature is blinded and restrained, has total cover against attacks and other effects outside the snake, and takes 21 (6d6) acid damage at the start of each of the titanoboa's turns. If the titanoboa takes 30 damage or more on a single turn from a creature inside it, the titanoboa must succeed on a DC 15 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the titanoboa. If the titanoboa dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 20 feet of movement, exiting prone.

Constrict

Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 27 (3d12 + 8) bludgeoning damage, and the target is grappled (escape DC 18). Until this grapple ends, the target is restrained, and the titanoboa can't constrict another target.