Death Burst.

When the mephit dies, it explodes in a burst of lava. Each creature within 5 feet of it must make a DC 11 Dexterity saving throw, taking 7 (2d6) fire damage on a failed save, or half as much damage on a successful one.

False Appearance.

While the mephit remains motionless, it is indistinguishable from an ordinary mound of magma.

Innate Spellcasting (1/Day).

The mephit can innately cast heat metal (spell save DC 10), requiring no material components. Its innate spellcasting ability is Charisma.

Actions

Claws.

Melee Weapon Attack: +3 to hit, reach 5 ft., one creature. Hit: 3 (1d4 + 1) slashing damage plus 2 (1d4) fire damage.

Fire Breath (Recharge 6).

The mephit exhales a 15-foot cone of fire. Each creature in that area must make a DC 11 Dexterity saving throw, taking 7 (2d6) fire damage on a failed save, or half as much damage on a successful one.

Magma Mephit