Ultroloth
Medium Fiend (yugoloth), Neutral EvilAC 19
HP 221 (26d8 + 104)
Speed 30 ft., fly 60 ft. (hover), (hover)
STR
19 (+4)
Save +4
DEX
16 (+3)
Save +3
CON
18 (+4)
Save +4
INT
19 (+4)
Save +4
WIS
15 (+2)
Save +2
CHA
18 (+4)
Save +4
Skills Deception +9, Perception +7, Stealth +8
Resistances Cold; Fire; Lightning
Immunities Acid; Poison
Condition Immunities Charmed, Frightened, Poisoned
Senses Truesight 120 ft., Passive Perception 17
Languages Abyssal, Infernal; telepathy 120 ft.
CR 13
Traits
Fiendish Restoration. If the ultroloth dies outside Gehenna, its body dissolves into ichor, and it gains a new body instantly, reviving with all its Hit Points somewhere in Gehenna.
Magic Resistance. The ultroloth has Advantage on saving throws against spells and other magical effects.
Actions
Multiattack. The ultroloth uses Hypnotic Gaze and makes two Mercurial Whip attacks.
Mercurial Whip. Melee Attack Roll: +9, reach 15 ft. Hit: 25 (6d6 + 4) Force damage, and the ultroloth can teleport the target up to 10 feet to an unoccupied space the ultroloth can see that isn't in the air.
Hypnotic Gaze. wis 17, each creature in a 30-foot Cone. Failure: 10 (3d6) Psychic damage, and the target has the Stunned condition until the start of the ultroloth's next turn. Success: The target is immune to this ultroloth's Hypnotic Gaze for 24 hours.