Special Equipment. Ras Nsi wears bracers of defense, wields a flame tongue longsword, and carries a sending stone matched to the one carried by the guide Salida (see chapter 1).

Shapechanger. Ras Nsi can use his action to polymorph into a Medium snake or back into his yuan-ti form. His statistics are the same in each form. Any equipment he is wearing or carrying isn't transformed. He doesn't change form if he dies.

Magic Resistance. Ras Nsi has advantage on saving throws against spells and other magical effects.

Innate Spellcasting. Ras Nsi's innate spellcasting ability is Charisma (spell save DC 16). He can innately cast the following spells, requiring no material components:

At will: animal friendship (snakes only)

3/day: suggestion

Spellcasting. Ras Nsi is an 11th-level spellcaster. His spellcasting ability is Intelligence (spell save DC 15, +7 to hit with spell attacks).

Ras Nsi has the following wizard spells prepared:

Cantrips (at will): chill touch, fire bolt, mage hand, mending, poison spray

1st level (4 slots): expeditious retreat, false life, magic missile, shield

2nd level (3 slots): blindness/deafness, hold person, misty step

3rd level (3 slots): animate dead, counterspell, fireball

4th level (3 slots): blight, polymorph

5th level (2 slots): contact other plane, geas

6th level (1 slot): create undead

Multiattack. Ras Nsi makes three melee attacks, but can use Constrict only once.

Bite (Snake Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:5 (1d4 + 3) piercing damage plus 7 (2d6) poison damage.

Constrict. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit:10 (2d6 + 3) bludgeoning damage, and the target is grappled (escape DC 14). Until this grapple ends, the target is restrained, and Ras Nsi can't constrict another target.

Flame Tongue Longsword (Yuan-ti Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:7 (1d8 + 3) slashing damage, or 8 (1d10 + 3) slashing damage when used with two hands, plus 7 (2d6) fire damage.