A magnetic marvel of nature, the ferrophlegm is a viscous metallic ooze that exhibits astonishing magnetic properties, allowing it to interact with and manipulate metal. Its grey metallic body propels itself forward by generating magnetic fields, a process that completely mystifies scholars and defies all logic. Like all metallic oozes, the ferrophlegm seeks out and consumes metal, preferring those that are more easily subjected to magnetism. The ooze’s presence is dramatic, causing metallic objects of considerable size and weight to zoom about at frightening speeds. For this reason, ferrophlegm are the bane of developed societies, generating veritable storms of shrapnel while they feed.


Huge ooze, unaligned

Armor Class 19 (natural armor)
Hit Points 220 (21d12 + 84)
Speed 40 ft., fly 40 ft. (hover)

23 (+6) 17 (+3) 19 (+4) 4 (-3) 12 (+1) 1 (-5)

Saving Throws Str +11, Wis +6
Skills Athletics +11, Perception +11
Damage Resistances bludgeoning, piercing, and slashing from metal weapons
Damage Immunities poison, psychic
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, prone
Senses blindsight 90 ft., blind beyond that radius, passive Perception 21
Challenge 13 (10,000 XP)


Amorphous. The ooze can move through a space as narrow as half an inch wide without squeezing. Additionally, other creatures can enter the ooze’s space, which is considered difficult terrain.

Deflection. Attacks made against the ooze with weapons that contain metal or that fire ammunition containing metal (such as bolts or arrows) are made at disadvantage.

Magnetic Fluid. The ooze’s body is magnetic. Whenever the ooze comes within 10 ft. of a metal object of Medium size or smaller for the first time on its turn or starts its turn within 10 ft. of such an object, it is drawn into the ooze’s body, becoming a part of its form and moving with the ooze as it moves. Objects being securely worn (such as armor) are immune to this effect, but more loosely secured items such as rings or necklaces are not. If the object is being carried or held, its wielder may attempt a DC 19 Strength saving throw to hold onto the object and prevent it from being drawn in. An object held within the ooze’s body can be removed by a creature taking an action to attempt a DC 19 Strength (Athletics) ability check, removing the object on a success.


Multiattack. The ooze makes two attacks and takes one other action.

Ferrokinesis. The ooze telekinetically moves a metal object of Huge size or smaller up to 90 ft. If the object ends this movement in the air, the ooze can suspend it there for as long as the object remains within 90 ft. of it. A creature attempting to physically move the target must take an action to make a Strength (Athletics) ability check contested by the oozes Strength (Athletics) ability check, or the attempt fails.

If the object is being worn or carried by a creature, it moves with the object unless it removes the object from its person.

Pseudopod. Melee Weapon Attack: +11 to hit, reach 20 ft., one target. Hit: 19 (2d12+6) bludgeoning damage. If the target is a creature, it must succeed on a DC 19 Constitution saving throw or become poisoned as it is injected with a portion of the ooze’s metallic body. The fluid of the ooze can be removed by a creature taking an action to attempt a DC 19 Wisdom (Medicine) ability check, ending the condition on a success.

Reverse Polarity. The ooze reverses the magnet charge in its body. Until the end of its next turn, metal objects within range of its Magnetic Fluid feature that would be drawn toward the ooze are instead pushed away from the ooze to the outside of the area. Additionally, attacks made with metallic weapons or ammunition against the ooze are made at disadvantage.

Magnetic Pulse (Recharge 5-6). Until the end of its next turn, the range the ooze’s magnetic fluid feature increases from 10 ft. to 60 ft.

Recall Fluid. A creature within 90 ft. poisoned by the ooze’s Pseudopod feature takes 55 (10d10) piercing damage and the poisoned condition ends.

Ref: TPKB1 p178