This unusual elemental seems to be made from magma and fire. Its skin is pitch black with glowing cracks forming and closing as it moves. Its face is featureless, except for a great flaming maw that sputters and smokes as it speaks.

Curious. Incinis are naturally curious creatures, and though they savor the taste of the living, they are likely to greet newcomers before attacking. An incinis is not naive or easily fooled, and it resorts to violence the instant it senses treachery or lies.

Volcanic Spirits. The incinis are often found on or near pools of magma, and seem to be capable to shaping and directing the flows of lava from active volcanoes.

Elemental Nature. The incinis doesn’t require air, food, drink, or sleep.

Incinis

Large elemental, neutral evil
Armor Class 17 (natural armor)
Hit Points 171 (18d10+72)
Speed 40 ft.

STR	DEX	CON	INT	WIS	CHA
12 (+1)	20 (+5)	18 (+4)	10 (+0)	16 (+3)	10 (+0)

Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities fire, poison
Condition Immunities exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 60 ft., passive Perception 13
Languages Common, Ignan
Challenge 10 (5,900 XP)

Magma Form. The elemental can move through a space as narrow as 1 inch wide without squeezing. A creature that touches the elemental or hits it with a melee attack while within 5 feet of it takes 5 (1d10) fire damage and must succeed on a DC 16 Strength saving throw or the weapon becomes stuck in the elemental. If the weapon’s wielder can’t or won’t let go of the weapon, the wielder is grappled while the weapon is stuck. While stuck, the weapon can’t be used. Until the grapple ends, the wielder takes 5 (1d10) fire damage at the start of each of its turns. To end the grapple, the wielder can release the weapon or pull it free by taking an action to make a DC 16 Strength check and succeeding.

Actions

Multiattack. The incinis makes two magma fist attacks.

Magma Fist. Melee Weapon Attack: +9 to hit, reach 10 ft., one creature. Hit: 14 (2d8 + 5) bludgeoning damage and 9 (2d8) fire damage.

Wave of Magma (Recharge 5-6). The incinis transforms into a wave of magma, moving up to its speed in a straight line. Each creature in the path where the incinis moves must make a DC 17 Dexterity saving throw. On a failure, a target takes 21 (6d6) fire damage and, if it is a Large or smaller creature, it is pushed ahead of the incinis and knocked prone in an unoccupied space within 5 feet of where the incinis ends its movement. On a success, a target takes half the damage and is neither pushed nor knocked prone.