Cerberus

Underworld Cerberus MOTp215  Large Monstrosity, Lawful EvilAC 16 (natural armor) Initiative +1 (11) HP 104 (11d10 + 44)Speed 60 ft.  modsave   modsave   modsaveStr19+4+4 Dex12+1+1 Con18+4+4Int10+0+0 Wis16+3+3 Cha9-1-1Skills Athletics +7, Perception +9, Stealth +4Immunities Fire, Necrotic; Blinded, Charmed, Deafened, Exhaustion, Frightened, StunnedSenses Truesight 30 ft., Passive Perception 19Languages Understands all languages but can't speakCR 6 (XP 2,300; PB +3)Traits Aggressive. As a bonus action, the cerberus can move up to its speed toward a hostile creature that it can see. Multiheaded. The cerberus can't be surprised, and it has advantage on saving throws against being knocked unconscious. Pack Tactics. The cerberus has advantage on an attack roll against a creature if at least one of the cerberus's allies is within 5 feet of the creature and the ally isn't incapacitated. Actions Multiattack. The cerberus makes three bite attacks. Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage plus 3 (1d6) fire damage. Breath Weapon (Recharge 5–6). The cerberus exhales a 30-foot cone of molten rock. Each creature in the cone must make a DC 15 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much damage on a successful one. On a failed save, a creature is also restrained by the hardening rock. A creature can make a DC 15 Strength (Athletics) check as an action, freeing itself or a creature within reach from the rock on a success. The rock has AC 17 and 20 hit points, and it is immune to fire, poison, and psychic damage.  Source: MOT, page 215