Yuan-Ti Pit Master

Yuan-Ti Pit Master CR: 5

Medium monstrosity (shapechanger, yuan-ti), neutral evil

Armor Class: 14 (natural armour)

Hit Points: 88 16d8+16

Speed: 28 ft

STR

16 +3

DEX

14 +2

CON

13 +1

INT

14 +2

WIS

12 +1

CHA

16 +3

Saving Throws: Wis +3, Cha +5

Skills: Deception +5, Stealth +4

Damage Immunities: Poison

Condition Immunities: Poison

Senses: Darkvision 120 ft (penetrates magical darkness), passive Perception 11

Languages: Abyssal, Common, Draconic

Challenge Rating: 5

Spellcasting (Yuan-Ti Form Only). The yuan-ti is a 6th level spellcaster. It's spellcasting ability is Charisma (spell save DC 13, +5 to hit with spell attacks). It regains it's spell slots after a Short or Long rest. It knows the following warlock spells:

At will: Eldritch Blast (300 ft, +3 bonus to each damage roll), Friends, Guidance, Magic Hand, Message, Poison Spray.

2/day: Command, Counterspell, Hellish Rebuke, Invisibility, Misty Step, Unseen Servant, Vampiric Touch.

Shapechanger. The yuan-ti can use it's action to polymorph into a Medium snake or back into it's true form. The statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. It doesn't change when it dies.
Innate Spellcasting (Yuan-Ti Form Only). The yuan-ti's innate spellcasting is Charisma (spell save DC 13). The yuan-ti can innately cast the following spells, requiring no material components:
At Will: Animal Friendship (snakes only) 3/Day: Suggestion.
Magic Resistance. The yuan-ti has advantage on saving throws against spells and other magical effects.
Poison's Disciple (2/Day). The first time the yuan-ti hits with a melee attack on it's turn, it can deal an extra 16 3d10 poison damage to the target.

Actions

Multiattack (Yuan-Ti Form Only). The yuan-ti makes two bite attacks using it's snake arms.
Bite. Melee Weapon Attack +5 to hit, reach 5 ft, one target. Hit 5 1d4+3 piercing damage plus 7 2d6 poison damage.
Merrshaulk's Slumber (1/Day). The yuan-ti targets up to five creatures that it can see within 60 feet of it. Each target must succeed on a DC 14 Constitution saving throw or fall into a magical sleep and be unconscious of 10 minutes. A sleeping target awakens if it takes damage or if someone uses an action to shake or slap it awake. The magical sleep has no effect on a creature immune to being charmed.

Pit Masters are another type of yuan-ti malison priest. They are traditionalists, and involved with many of their species long-term plans. Each pit master is deeply involved in the overtaking of other humanoid governments, the safety of their own cities, preventing the latter from either discovery or attack by hostile forces. They are generally human in shape with their arms replaced by one or more snakes.

Suggested Environments

Tropical and sub-tropical regions.