Armor Class 16 (natural armor)
Hit Points 104 (11d10 + 44)
Speed 60 ft.
Skills Athletics +7, Perception +9, Stealth +4
Damage Immunities fire, necrotic
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, stunned
Senses truesight 30 ft., passive Perception 19
Languages understands all languages but can't speak
Challenge 6
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.
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.
Mythic Odysseys of Theros, p. 215