Conflagration Ooze

Amorphous. The conflagration ooze can move through a space as narrow as 1 inch wide without squeezing.

Death Burs. When the conflagration ooze dies, it explodes in a burst of fire and magma. Each creature within 10 feet of it must make a DC 14 Dexterity saving throw, taking 14 (4d6) fire damage on a failed save, or half as much damage on a successful one. Flammable objects that aren't being worn or carried in that area are ignited.

Innate Spellcasting. The conflagration ooze's innate spellcasting ability is Charisma (spell save DC 13). It can innately cast the following spells, requiring no material components:
1/day each:  confusion, hold monster, sleep

Fire in the Blood: A potent fiery toxin flows through the body of a conflagration ooze. Any creature grappled or pinned by the ooze must make a successful DC 16 Constitution save as the fiery toxin seeps through the victim's skin (or whatever surface passes for its skin) and into its blood (or life-supporting fluid, such as sap in a plant creature). Success indicates the creature takes 1d6 points of fire damage in addition to any damage already dealt by the slam or grapple, as the fire burns and sears the creature. Failure indicates that the toxin has taken hold of the creature's body and has begun converting portions of its blood into liquid flame. The creature takes 1d4 points of Constitution damage and 2d6 points of fire damage, in addition to any damage already dealt by the slam or grapple. Each round the creature remains grappled by the ooze, and for 1 round afterward, it must make another DC 16 Constitution save to reduce or avoid the same effects.

As a creature that fails its saves takes Constitution damage, the flaming blood burns through the victim's skin in small patches that increase in size the more Constitution damage accrues. Tiny rivulets of flame leak from these holes, as well as from the creature's ears, nose, and mouth, running down the victim's body and giving it an unearthly, terrible appearance.

Multiattack. The conflagration ooze makes two slam attacks.

Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage plus 7 (2d6) fire damage, and the target must succeed on a DC 14 Constitution saving throw or be poisoned for 1 minute. While poisoned in this way, the target's blood turns to liquid fire and it takes 7 (2d6) fire damage at the start of each of its turns. A creature can repeat the saving throw at the start of each of its turns, ending the effect on itself on a success.