Armor Class 13 (natural armor)
Hit Points 33 (6d8 + 6)
Speed 30 ft.
Damage Resistances cold, fire, lightning
Damage Immunities poison
Condition Immunities charmed, frightened, poisoned
Senses darkvision 60 ft., passive Perception 9
Languages understands Abyssal but can't speak
Challenge 1
Rampage. When it reduces a creature to 0 hit points with a melee attack on its turn, the maw demon can take a bonus action to move up to half its speed and make a bite attack.
Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 11 (2d8 + 2) piercing damage.
Volo's Guide to Monsters, p. 137