Innate Spellcasting. The couatl's spellcasting ability is Charisma (spell save DC 12). It can innately cast the following spells, requiring only verbal components:

1/day each: bless, create food and water, cure wounds,  protection from poison

Magic Weapons. The couatl's weapon attacks are magical.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 8 (1d6 + 4) piercing damage, and the target must succeed on a DC 10 Constitution saving throw or be poisoned for 1 hours. Until this poison ends, the target is unconscious. Another creature can use an action to shake the target awake.

Constrict. Melee Weapon Attack: +3 to hit, reach 10 ft., one Medium or smaller creature. Hit: 10 (2d6 + 1) bludgeoning damage, and the target is grappled (escape DC 14). Until this grapple ends, the target is grappled, and the couatl can't constrict another target.