Magmin

(From 5th Edition Monster Manual - 2014):

A grinning, mischievous magmin resembles a stumpy humanoid sculpted from a black shell of magma. Even when it isn’t ablaze and radiating heat like a bonfire, small jets of flame erupt from its porous skin.

Summoned Pyromaniacs. Magmins are fire elemental spirits bound into physical forms by magic, and they appear in the Material Plane only when summoned. They view flammable objects as kindling for a grand conflagration, and only the magical control exerted by their summoners keeps them from setting everything they touch ablaze. Their propensity for fire and havoc makes them ideal for spreading chaos and destruction. A mob of magmins summoned inside a castle can reduce it to a burning shell within minutes.

Fiery Destruction. Although its flame is potent, the magmin’s hard magma shell prevents it from instantly igniting everything it comes into contact with. However, like the fires inside them, magmins are capricious and unpredictable. Moreover, as simple elemental creations, they are oblivious to the harm their native element causes creatures of the Material Plane.

If it has the opportunity while in service to its master, a magmin seeks out areas of great heat, such as forest fires or the bubbling magma of an active volcano. At other times, a magmin compulsively looses fire from its fingertips, delighting in setting objects ablaze.

(From Monster Manual v3.5 - 2003):

This glowing, humanoid creature looks like a stumpy human sculpted from fire and flowing lava. It radiates heat like a small bonfire, and it has a gleeful, almost mali cious smile on its face. 

Magmins are small. human-shaped beings from the Elemental Plane of Fire that radiate intense heat and are wreathed in an aura of searing flames. 

Although not evil, these fiery creatures are extremely mischievous. They like to watch things burn, perhaps lacking the ability to understand that flames arepainful or even deadly to other creatures. 

A typícal magmin is 4 feet tall and weighs 400 pounds. 

Magmins speak Ignan. 

Combat: Although small, magmins are dangerous opponents. Their touch is effective against those who lack protection or immunity from heat and flames, but if faced with opponents who have immunity to fire, magmins rely on their slam attack. In any case, magmins are not valiant fighters. They usually flee if injured, although often only far enough to set up a fiery ambush for their enemies. 

A magmin's natural weapons are treated as magic weapons for the purpose of overcoming damage reduction. 

Combustion (Ex): Anyone a magmin touches must succeed on a DC 12 Reflex save or take an extra 1d8 points of fire damage as clothes ignite or armor becomes searing hot. The damage continues for another 1d4+2 rounds after the magmin's last successful attack. Magmins can also ignite flammable materials with a touch. The save DC is Constitution-based.

Fiery Aura (Ex): Anyone within 20 feet of a magmin must suc ceed on a DC 12 Fortitude save or take 1d6 points of heat damage per round from the intense heat. The save DC is Constitution-based. 

Melt Weapons (Ex): Any metal weapon that strikes a magmin must succeed on a DC 12 Fortitude save or melt away into slag. The save DC is Constitution-based.

(From Planescape Campaign Setting - 1994):

Magmen are creatures of the Paraelemental Plane of Magma. They stand 3 feet tall and are glowing, humanoid creatures, much like fire-cloaked gnomes or goblins. Small puffs of flame constantly burst from their skin, as if they are perspiring kerosene that ignites when enough accumulates. Magmen radiate heat like small bonfires, rendering the area near them quite uncomfortable to most nonfire-loving creatures. Their faces are almost always twisted with malicious glee.

Combat: Magmen are not really interested in fighting, but they are capricious little creatures who cause havoc by their very natures. Whenever they encounter an unfamiliar creature, which — their being from the plane of Magma — is almost anything else, they try to set it on fire, just for fun. Perhaps they do not understand that others fear their flames, or perhaps they do and don’t care. Any attempt to reason them out of this course of action is almost certainly doomed to fail. At best, a creature might bribe them off with another target or a choice bit of burning food.

In combat, they attack simply with a touch. Their flaming fingers ignite the flammable items (clothing, hair, etc.) of any creature they hit, inflicting 1d8 points of damage per round for 1d4 + 2 rounds. Note that extraordinarily flammable carried items — flasks of oil and the like — must successfully save vs. normal fire or they, too, will ignite and cause their own, additional damage. This check is made once per round until the flames are out or the victim discards the item. Also, combustible magical items (scrolls, etc.) must make their own successful saving throws or be destroyed. Again, the check is made once each round unless the item is discarded.

Magmen aren’t fighters and, if attacked and actually hurt, their first choice is to run away — not too far away, but far enough to be out of immediate danger. Once safe, they are curious and foolish enough to return. If cornered, magmen will defend themselves, striking with a molten fist and inflicting 3d8 points of damage upon a successful hit. Fire-resistant creatures, including those protected by magic, suffer only half damage from such an attack.

Magmen are not easy to hurt, however. A weapon of +1 or better enchantment is required to hit them. In addition, weapons of less than +2 enchantment must save vs. magical fire upon every successful hit. If the save is failed, the weapon melts into useless slag. Not surprisingly, magmen are immune to all fire-based attacks. Conversely, cold-based attacks inflict double damage and prompt morale checks.

Habitat/Society: Magmen are creatures of the Paraelemental Plane of Magma, and as such they have no society on other planes. When they appear outside their own fiery lands, their sole preoccupation seems to be with having fun… by their standards. Magmen love flame and are fascinated with burning things. Were it not for the damage their curiosity causes, their childlike pleasure might almost be touching or amusing. Somehow, it never occurs to these creatures (or if it does, they perversely ignore it) that other creatures might actually be hurt by their actions. Having come from an environment of fire, the panic-stricken reaction of Prime Material creatures who are set afire seems merely comical to them, almost slapstick. Perhaps this is because the association of pain and fire is utterly foreign to their kind.

On their own plane, magmen live as hunter-gatherers. They band in small tribes, organized around a single extended “colony”. (Colony is the only apt word, for magmen have no sexes, reproducing by simple division as they grow.) Each tribe is led by the eldest magman. They scour the molten plain, looking for choice bits of flaming minerals or hunting other elemental creatures.

Occasionally, magmen pass into other Inner Planes or the Prime Material Plane through gaps created by the excessive heat and pressure of subterranean lava. These portals have a strong lure to the magmen, for the molten stone of such gaps has a different “taste” than that of their home. Magmen enter into the vortex to sample the essence, and they are invariably drawn through the portal and into the other plane. Some sages speculate that the strange minerals of these portals may have an intoxicating effect on the little creatures. This would certainly account for their frivolous behavior outside of their plane.

Magmen can reach the Outer Planes only if they are summoned. Their mischievous and destructive natures provide perverse amusement to tanar’ri and baatezu, and these fiends sometimes keep magmen captive in special molten pools. Magmen are sometimes summoned into the midst of enemy ranks in the Gray Waste, Gehenna, and Carceri, providing diversionary attacks in the never-ending Blood War. Militarily, they are good for little more than this, since their flightiness and cowardice make them unsuitable for pitched combat.

Magmen especially like to swim around in active volcanoes, for when these erupt, the magmen are released to engage in their favorite sport of igniting all the combustible materials they can reach. Magmen can remain out of lava or some other fiery habitat for a maximum of six hours before they stiffen and become immobile. They rarely remain away from their environment for more than two or three hours at a time, as they consider anything below 1,000�F to be uncomfortably cold.

Magmen speak their own and no other languages.

Ecology: Most sages and travelers guess that magmen eat choice morsels of molten rock, although it is possible that they absorb much of their nutrients directly through the skin.

Upon occasion, a wizard will summon a magman to fire a furnace for a magical procedure, but wise wizards return the little troublemaker as soon as the need has passed. Some are tempted to trap the creatures and let them cool, since magmen statuettes are sometimes collected as garden ornaments for the wealthy. However, imminent death makes the little beings hostile and dangerous, and more than a few city blocks have been destroyed in their attempted escapes.