Cinderclaw

The Burning Heart. Cinderclaw is attuned to an ancient Draconic artifact, the Burning Heart. The Burning Heart has HP:40 and AC:15, and acts on initiative count 20 of each round. Dealing damage to the Burning Heart deals double damage to Cinderclaw, and destroying it causes him disadvantage on attacks for the next 24 hours. The Burning Heart causes the following effects each turn:

- Restores 5 HP to Cinderclaw, increases his AC by 3, adds 1d6 fire damage to all attacks (included in attacks), and gives vulnerability to cold damage for 1 round

- Deals 1d8 fire damage to any creature that hits it with a melee attack

- Summons 1d3 Magmin out of nearby lava

Multiattack. Cinderclaw makes two attacks: one with its bite and one with its claws.

Bite. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 10 (1d10 + 4) piercing damage plus 3 (1d6) fire damage plus an additional 3 (1d6) fire damage if the Burning Heart is active

Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d6 + 4) slashing damage plus an additional 3 (1d6) fire damage if the Burning Heart is active.

Fire Breath (Recharge 5–6). The dragon exhales fire in a 30-foot cone. Each creature in that area must make a DC 13 Dexterity saving throw, taking 24 (7d6) fire damage on a failed save, or half as much damage on a successful one.