Hell Hound

Medium fiend, lawful evil

Armor Class 15 (natural armor)

Hit Points 45 (7d8+14)

Speed 50ft.

Skills Perception +5

Damage Immunities fire

Senses darkvision 60ft., passive Perception 15

Languages understands Infernal but can't speak it

Challenge 3 (700 XP)

Traits

Keen Hearing and Smell

The hound has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Pack Tactics

The hound has advantage on an attack roll against a creature if at least one of the hound's allies is within 5ft of the creature and the ally isn't incapacitated.

Actions

Bite

Melee Weapon Attack: +5 to hit, reach 5ft., one target.
Hit: 7 (1d8+3) piercing damage plus 7 (2d6) fire damage.

Fire Breath (Recharge 5-6)

The hound exhales fire in a 15ft cone. Each creature in that area must make a DC 12 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much damage on a successful one.