Hungry Slag
Medium • Ooze • Unaligned
Armor Class 15
Hit Points 90 (12d8 + 36)
Speed 20 ft.
Initiative -3 (7)
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 18 (+4) | 5 (-3) | 16 (+3) | 2 (-4) | 6 (-2) | 2 (-4) |
Damage Resistances acid, cold
Damage Immunities fire
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, grappled, restrained
Senses blindsight 60 ft., passive Perception 8
Languages –
CR 5 (XP 1,800; PB +3)
Amorphous. The slag can move through a Tiny space without expending extra movement to do so.
Liquefy and Stiffen. If the slag is subjugated to fire damage, its speed increases by 10 feet until the end of its next turn. If the slag takes cold damage, its speed decreases by 10 feet until the end of its next turn. Each effect can only happen once per round.
Metal Eater. Nonmagical ammunition is destroyed immediately after hitting the ooze and dealing any damage. Any nonmagical metallic weapon takes a cumulative -1 penalty to attack rolls immediately after dealing damage to the ooze and coming into contact with it. The weapon is destroyed if the penalty reaches -5. The penalty can be removed by casting the mending spell on the weapon. The ooze can eat through 1-inch-thick, nonmagical metal in 1 round.
Metal Sense. The sludge knows the distance and direction to any metal within 100 feet of it.
Unusual Nature. The slag doesn't require air or sleep.
Water Susceptibility. The slag takes 3 (1d6) cold damage for every 5 feet the slag moves in water or for every gallon of water splashed on it.
ACTIONS
Multiattack. The slag makes two Heated Pseudopod attacks.
Heated Pseudopod. Melee Weapon Attack: +7, reach 5 ft. Hit: 8 (1d8 + 4) fire damage plus 7 (2d6) acid damage. When a creature made out of metal or wearing metallic armor is hit three times by this attack within 1 minute, it suffers the effect of the heat metal spell for 1 minute or until it is doused in water.
Slag Throw. Ranged Weapon Attack: +7, reach 30 ft. Hit: 18 (4d6 + 4) bludgeoning damage plus 9 (2d8) fire damage, and a Medium or smaller target is knocked prone.
REACTIONS
Heat Surge (Recharge 5-6). Trigger: The slag takes damage, other than cold damage. Response - Constitution Saving Throw: DC 14, each creature in a 5-foot emanation originating from the slag. Failure: 9 (2d8) fire damage. Success: Half damage.
Hungry Slag
Medium • Ooze • Unaligned
Armor Class 14
Hit Points 39 (6d8 + 12)
Speed 20 ft.
Initiative -3 (7)
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 16 (+3) | 5 (-3) | 14 (+2) | 2 (-4) | 6 (-2) | 2 (-4) |
Damage Resistances acid, cold
Damage Immunities fire
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, grappled, restrained
Senses blindsight 60 ft., passive Perception 8
Languages –
CR 2 (XP 450; PB +2)
Amorphous. The slag can move through a Tiny space without expending extra movement to do so.
Liquefy and Stiffen. If the slag is subjugated to fire damage, its speed increases by 10 feet until the end of its next turn. If the slag takes cold damage, its speed decreases by 10 feet until the end of its next turn. Each effect can only happen once per round.
Metal Eater. Nonmagical ammunition is destroyed immediately after hitting the ooze and dealing any damage. Any nonmagical metallic weapon takes a cumulative -1 penalty to attack rolls immediately after dealing damage to the ooze and coming into contact with it. The weapon is destroyed if the penalty reaches -5. The penalty can be removed by casting the mending spell on the weapon. The ooze can eat through 1-inch-thick, nonmagical metal in 1 round.
Metal Sense. The sludge knows the distance and direction to any metal within 100 feet of it.
Unusual Nature. The slag doesn't require air or sleep.
Water Susceptibility. The slag takes 3 (1d6) cold damage for every 5 feet the slag moves in water or for every gallon of water splashed on it.
ACTIONS
Multiattack. The slag makes two Heated Pseudopod attacks.
Heated Pseudopod. Melee Weapon Attack: +5, reach 5 ft. Hit: 6 (1d6 + 3) fire damage plus 3 (1d6) acid damage. When a creature made out of metal or wearing metallic armor is hit four times by this attack within 1 minute, it suffers the effect of the heat metal spell for 1 minute or until it is doused in water.
Slag Throw. Ranged Weapon Attack: +5, reach 30 ft. Hit: 6 (1d6 + 3) bludgeoning damage plus 4 (1d8) fire damage, and a Medium or smaller target is knocked prone.
REACTIONS
Heat Surge (Recharge 5-6). Trigger: The slag takes damage, other than cold damage. Response - Constitution Saving Throw: DC 12, each creature in a 5-foot emanation originating from the slag. Failure: 4 (1d8) fire damage. Success: Half damage.
Hungry Slag
Medium • Ooze • Unaligned
Armor Class 16
Hit Points 127 (15d8 + 60)
Speed 20 ft.
Initiative -3 (7)
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 19 (+4) | 5 (-3) | 18 (+4) | 2 (-4) | 6 (-2) | 2 (-4) |
Damage Resistances acid, cold
Damage Immunities fire
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, grappled, restrained
Senses blindsight 60 ft., passive Perception 8
Languages –
CR 8 (XP 3,900; PB +3)
Amorphous. The slag can move through a Tiny space without expending extra movement to do so.
Liquefy and Stiffen. If the slag is subjugated to fire damage, its speed increases by 10 feet until the end of its next turn. If the slag takes cold damage, its speed decreases by 10 feet until the end of its next turn. Each effect can only happen once per round.
Metal Eater. Nonmagical ammunition is destroyed immediately after hitting the ooze and dealing any damage. Any nonmagical metallic weapon takes a cumulative -1 penalty to attack rolls immediately after dealing damage to the ooze and coming into contact with it. The weapon is destroyed if the penalty reaches -5. The penalty can be removed by casting the mending spell on the weapon. The ooze can eat through 1-inch-thick, nonmagical metal in 1 round.
Metal Sense. The sludge knows the distance and direction to any metal within 100 feet of it.
Unusual Nature. The slag doesn't require air or sleep.
Water Susceptibility. The slag takes 3 (1d6) cold damage for every 5 feet the slag moves in water or for every gallon of water splashed on it.
ACTIONS
Multiattack. The slag makes two Heated Pseudopod attacks.
Heated Pseudopod. Melee Weapon Attack: +7, reach 5 ft. Hit: 11 (2d6 + 4) fire damage plus 10 (3d6) acid damage. When a creature made out of metal or wearing metallic armor is hit three times by this attack within 1 minute, it suffers the effect of the heat metal spell for 1 minute or until it is doused in water.
Slag Throw. Ranged Weapon Attack: +7, reach 30 ft. Hit: 21 (5d6 + 4) bludgeoning damage plus 10 (3d6) fire damage, and a Medium or smaller target is knocked prone.
REACTIONS
Heat Surge (Recharge 5-6). Trigger: The slag takes damage, other than cold damage. Response - Constitution Saving Throw: DC 15, each creature in a 5-foot emanation originating from the slag. Failure: 13 (3d8) fire damage. Success: Half damage.
QUICK REFERENCE
Habitat
- Found near forges, foundries, or volcanic environments where metalworking or molten materials are common
- Lurks in battlefields, scrapyards, or ruins rich in discarded weapons and armor
- Dwells in deep caverns where natural heat sources or magma flows provide ideal conditions
Behavior
- Moves slowly and directionlessly or not at all until sensing metal, at which point it becomes highly focused
- Consumes metallic objects methodically, leaving piles of stone, wood, and fabric
- Reacts to temperature changes with visible agitation, shuddering when cold or rippling smoothly when heated
Information (Intelligence Check)
- DC 12 Nature: direct contact with water harms it, the more water the better
- DC 14 Perception: the slag becomes faster when exposed to fire and slower when exposed to cold
- DC 16 Investigation: metal equipment struck repeatedly against it rapidly corrodes, risking permanent destruction
Combat
- Focuses attacks on characters wearing heavy armor or wielding prominent metal weapons
- Uses Slag Throw to knock prone mobile or distant targets, creating openings for further heated attacks
- Triggers its Heat Surge reaction frequently in multi-attacker situations to punish clustered melee fighters
- Retreat only when it has enough metal destroyed/eaten or no more metal is available to eat
Loot Ideas
- Semi-melted metal chunks suitable for smelting into ingots of valuable materials, such as adamantine, mithril, platinum, or similar
- Preserved yet damaged non-metal belongings from previous victims that the slag ignored, such as pouches, scrolls, or valuables in the vicinity
USING MONSTER VARIANTS
Monster variants allow the GM to adjust encounters to better match the party’s strength, narrative needs, or world-building logic. A weaker variant may represent a juvenile, wounded, or lesser specimen, while a stronger variant can serve as a leader, champion, ancient creature, or apex predator.
Variants can be used to fine-tune difficulty without changing the core identity of the monster, making them ideal for scaling encounters, reinforcing hierarchy within a faction, or creating memorable boss-style enemies. You can even use the same stat block but different variants in the same encounter if you want.
Design Note. Each monster is primarily balanced around its normal version. Weaker and stronger variants are derived adjustments and may not always preserve every tactical nuance or “feel” of the original creature. GMs are encouraged to review variants carefully and adjust abilities or tactics as needed to best suit their table.