Hell Hound

5e compatible shield

Medium fiend, lawful evil

Armor Class 15 (natural armor)
Hit Points 45 (7d8 + 14)
Speed 50 ft.

STR DEX CON INT WIS CHA
17 (+3) 12 (+1) 14 (+2) 6 (-2) 13 (+1) 6 (-2)

Saving Throws 
Skills Perception +5
Damage Resistances 
Damage Immunities fire
Condition Immunities 
Senses darkvision 60 ft., passive Perception 15
Languages understands Infernal but can't speak it
Challenge 3 (700 XP)

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 5 feet of the creature and the ally isn’t incapacitated.

Actions

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

Fire Breath (Recharge 5–6). The hound exhales fire in a 15-foot 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.