Relentless. If the Giant Constrictor Snake takes 10 damage or less that would reduce it to 0 hit points, it is reduced to 1 hit point instead if it succeeds a DC 13 CON save.

Poisoned Dead. Any creatures hit by an attack of this creature must succeed a DC 12 CON Save or take (2d4) extra poison damage.

Bite. Melee Weapon Attack: +6 to hit, reach 10 ft., one creature. Hit: 11 (2d6 + 4) piercing damage.

Constrict. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 13 (2d8 + 4) bludgeoning damage, and the target is grappled (escape DC 16). Until this grapple ends, the creature is restrained, and the snake can't constrict another target.