Innate Spellcasting. The yuan-ti’s innate spellcasting ability is Charisma (spell save DC 15). The yuan-ti can innately cast the following spells, requiring no material components:

At will: animal friendship (snakes only)

3/day: suggestion

1/day: fear

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

Multiattack. The yuan-ti mummy makes two ranged attacks or three melee attacks, but can use its rotting bite and constrict attacks only once each and can replace one for Dreadful Glare.

Rotting Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 4) peircing damage plus 10 (3d6) necrotic damage. If the target is a creature, it must succeed on a DC 15 Constitution saving throw or be cursed with mummy rot. The cursed target can't regain hit points, and its hit point maximum decreases by 10 (3d6) for every 24 hours that elapse. If the curse reduces the target's hit point maximum to 0, the target dies, and its body turns to dust. The curse lasts until removed by the remove curse spell or other magic.

Dreadful Glare. The mummy targets one creature it can see within 60 feet of it. If the target can see the mummy, it must succeed on a DC 13 Wisdom saving throw against this magic or become frightened until the end of the mummy's next turn. If the target fails the saving throw by 5 or more, it is also paralyzed for the same duration. A target that succeeds on the saving throw is immune to the Dreadful Glare of all mummies (but not mummy lords) for the next 24 hours.

Constrict. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage, and the target is grappled (escape DC 14). Until this grapple ends, the target is restrained, and the yuan-ti can’t constrict another target.

Scimitar. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage.

Longbow. Ranged Weapon Attack: +6 to hit, range 150/600 ft., one target. Hit: 12 (2d8 + 3) piercing damage plus 10 (3d6) poison damage.