Volo's Guide to Monsters
Maw Demon CR: 1
Medium fiend (demon), chaotic evil
Armor Class: 13 (Natural Armor)
Hit Points: 33 (6d8 + 6)
Speed:
30 ft
Damage Resistances: Cold, Fire, Lighting
Damage Immunities: Poison
Condition Immunities: Charmed, Frightened, Poisoned
Senses: Darkvision 60ft., Passive Perception 9
Languages: Understands Abyssal but can't speak
Challenge Rating: 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.
Actions
Bite: Melee Weapon Attack: +4 to hit, reach 5f., one target. Hit: 11 (2d8) piercing damage.