Innate Spellcasting (Yuan-Ti Form Only). The yuan-ti's innate spellcasting ability is Charisma (spell save DC 13). The yuan-ti can innately cast the following spells, without providing material components:

At will: animal friendship (snakes only), druidcraft

3/day: suggestion

Magic Resistance. The yuan-ti has advantage on saving throws against spells and other magical effects.

Magic Ranged Weapons. The yuan-ti's ranged weapon attacks are magical.

Shapechanger. The yuan-ti can use its action to polymorph into a Medium snake, or back into its true form. Its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. It doesn't change form if it dies.

Multiattack (Yuan-Ti Form Only). The yuan-ti makes three ranged attacks or two melee attacks, but can constrict only once.

Bite (Snake Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 6 (1d4 + 4) piercing damage plus 7 (2d6) poison damage.

Constrict. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 2) bludgeoning damage, and the target is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the yuan-ti can't constrict another target.

Scimitar (Yuan-ti Form Only). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage.

Longbow (Yuan-ti Form Only). Ranged Weapon Attack: +7 to hit, range 150/600 ft., one target. Hit: 8 (1d8 + 4) piercing damage plus 7 (2d6) poison damage.

Arcane Shot (2/Day). As a bonus action, when the yuan-ti hits a target with a ranged weapon attack, it can choose one from the following three effects:

1. Bursting Arrow. The target and all other creatures within 10 feet of it take an extra 7 (2d6) force damage each.
2. Shadow Arrow. If the target is a creature, it takes an extra 7 (2d6) psychic damage and the creature must succeed on a DC 13 Wisdom saving throw or be unable to see anything farther than 5 feet away until the start of the yuan-ti's next turn.