Sources
CR
Type
Size
Alignment
Movement

Green Abishai

Medium Fiend (devil), Lawful Evil

Armor Class 18 (natural armor)
Hit Points 195 (26d8 + 78)
Speed 30 ft., fly 40 ft.
STR
12
+1
DEX
17
+3
CON
16
+3
INT
17
+3
WIS
12
+1
CHA
19
+4
Saving Throws INT +8, CHA +9
Skills Deception +9, Insight +6, Perception +6, Persuasion +9
Damage Resistances cold; bludgeoning, piercing, slashing, from nonmagical attacks that aren't silvered
Damage Immunities fire, poison
Condition Immunities Poisoned
Senses darkvision 120 ft., passive Perception 16
Languages Draconic, Infernal, telepathy 120 ft.
Challenge 15 (13,000 XP)

Traits

Devil's Sight. Magical darkness doesn't impede the abishai's darkvision.

Magic Resistance. The abishai has advantage on saving throws against spells and other magical effects.

Spellcasting

Spellcasting. The abishai casts one of the following spells, requiring no material components and using Charisma as the spellcasting ability (spell save DC 17):

At will: alter self, major image

1/day each: confusion, dominate person, mass suggestion

3/day each: charm person, detect thoughts, fear

Actions

Multiattack. The abishai makes two Fiendish Claw attacks, or it makes one Fiendish Claw attack and uses Spellcasting.

Fiendish Claw. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit:12 (2d8 + 3) force damage. If the target is a creature, it must succeed on a DC 16 Constitution saving throw or take 16 (3d10) poison damage and become poisoned for 1 minute. The poisoned target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Lore

Each abishai was once a mortal who somehow won Tiamat's favor before death and, as a reward, found its soul transformed into a draconic devil to serve at her pleasure in the Nine Hells. Each type of abishai is associated with one of Tiamat's five dragon heads: black, blue, green, red, and white.