Armor Class 14 (natural armor)
Hit Points 71 (13d8 + 13)
Speed 30 ft.
Saving Throws WIS +4, CHA +5
Skills Deception +5, Stealth +4
Damage Immunities poison
Condition Immunities poisoned
Senses darkvision 120 ft., passive Perception 12
Languages Abyssal, Common, Draconic
Challenge 4
Devil's Sight. Magical darkness doesn't impede the yuan-ti's darkvision.
Magic Resistance. The yuan-ti has advantage on saving throws against spells and other magical effects.
Sseth's Blessing. When the yuan-ti reduces an enemy to 0 hit points, the yuan-ti gains 9 temporary hit points.
Multiattack. The yuan-ti makes two Bite attacks and one Scimitar attack, or it makes two Spectral Fangs attacks.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) piercing damage plus 7 (2d6) poison damage.
Scimitar (Yuan-ti Form Only). Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage.
Spectral Fangs. Ranged Spell Attack: +5 to hit, range 120 ft., one target. Hit: 16 (3d8 + 3) psychic damage.
Change Shape. The yuan-ti transforms 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. If it dies, it stays in its current form.
Mordenkainen Presents: Monsters of the Multiverse, p. 274