Howler

Large fiend, chaotic evil
Armor Class 16 (natural armor)
Hit Points 90 (12d10 + 24)
Speed 40 ft.
STR
17 (+3)
DEX
16 (+3)
CON
15 (+2)
INT
5 (-3)
WIS
20 (+5)
CHA
6 (-2)
Skills Perception +8
Damage Resistances cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunities frightened
Senses darkvision 60 ft., passive Perception 15
Languages understands Abyssal but can't speak
Challenge 8 (3900 XP)
Pack Tactics.
ACTIONS
Multiattack.
Rending Bite.
Mind-Breaking Howl (Recharge 6).

This full creature's stat block is not available (not OGL).

Mordenkainen´s Tome of Foes
Howler