Rust Elemental
Large • Elemental • Neutral Evil
Armor Class 14
Hit Points 110 (13d10 + 39)
Speed 10 ft., fly 60 ft. (hover)
Initiative +4 (14)
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 15 (+2) | 18 (+4) | 16 (+3) | 6 (-2) | 10 (+0) | 7 (-2) |
Damage Resistances acid; bludgeoning, piercing, slashing
Damage Immunities poison
Condition Immunities exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 60 ft., passive Perception 10
Languages Primordial (Auran)
CR 7 (XP 2,900; PB +3)
Air Form. The elemental can enter a creature's space and stop there. It can move through a space as narrow as 1 inch without expending extra movement to do so.
Iron Scent. The elemental can pinpoint the location of ferrous metal within 30 feet of itself.
Poisonous Air. Constitution Saving Throw: DC 14, any creature that starts its turn inside the space of the elemental. Failure: The target becomes poisoned until the start of its next turn.
Unusual Nature. The elemental doesn't require air, food, drink, or sleep.
ACTIONS
Multiattack. The elemental makes two Corroding Slam attacks.
Corroding Slam. Melee Weapon Attack: +7, reach 5 ft. Hit: 22 (4d8 + 4) acid damage. Miss - Dexterity Saving Throw: DC 14. Failure: A metallic nonmagical armor or shield takes a -1 penalty to the AC it offers (armor). Armor is destroyed if the penalty reduces its AC to 10. The penalty can be removed by casting the Mending spell on the armor or weapon.
Oxidizing Whirlwind (Recharges after a Rest). Constitution Saving Throw: DC 14, each creature in a 30-foot cone. Failure: 22 (4d10) bludgeoning damage. Nonmagical metallic objects that affected creatures are wearing or carrying take a -1 penalty to the AC they offer (armor) or to their attack rolls (weapon). Armor is destroyed if the penalty reduces its AC to 10, and a weapon is destroyed if its penalty reaches -5. The penalty can be removed by casting the Mending spell on the armor or weapon.
Rust Elemental
Large • Elemental • Neutral Evil
Armor Class 13
Hit Points 67 (9d10 + 18)
Speed 10 ft., fly 60 ft. (hover)
Initiative +3 (13)
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 13 (+1) | 16 (+3) | 14 (+2) | 6 (-2) | 10 (+0) | 7 (-2) |
Damage Resistances acid; bludgeoning, piercing, slashing
Damage Immunities poison
Condition Immunities exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 60 ft., passive Perception 9
Languages Primordial (Auran)
CR 4 (XP 1,100; PB +2)
Air Form. The elemental can enter a creature's space and stop there. It can move through a space as narrow as 1 inch without expending extra movement to do so.
Iron Scent. The elemental can pinpoint the location of ferrous metal within 30 feet of itself.
Poisonous Air. Constitution Saving Throw: DC 12, any creature that starts its turn inside the space of the elemental. Failure: The target becomes poisoned until the start of its next turn.
Unusual Nature. The elemental doesn't require air, food, drink, or sleep.
ACTIONS
Multiattack. The elemental makes two Corroding Slam attacks.
Corroding Slam. Melee Weapon Attack: +5, reach 5 ft. Hit: 13 (3d6 + 3) acid damage. Miss - Dexterity Saving Throw: DC 12. Failure: A metallic nonmagical armor or shield takes a -1 penalty to the AC it offers (armor). Armor is destroyed if the penalty reduces its AC to 10. The penalty can be removed by casting the Mending spell on the armor or weapon.
Oxidizing Whirlwind (Recharges after a Rest). Constitution Saving Throw: DC 12, each creature in a 30-foot cone. Failure: 13 (3d8) bludgeoning damage. Nonmagical metallic objects that affected creatures are wearing or carrying take a -1 penalty to the AC they offer (armor) or to their attack rolls (weapon). Armor is destroyed if the penalty reduces its AC to 10, and a weapon is destroyed if its penalty reaches -5. The penalty can be removed by casting the Mending spell on the armor or weapon.
Rust Elemental
Large • Elemental • Neutral Evil
Armor Class 15
Hit Points 152 (16d10 + 64)
Speed 10 ft., fly 60 ft. (hover)
Initiative +5 (15)
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 17 (+3) | 20 (+5) | 18 (+4) | 6 (-2) | 12 (+1) | 7 (-2) |
Damage Resistances acid; bludgeoning, piercing, slashing
Damage Immunities poison
Condition Immunities exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 60 ft., passive Perception 11
Languages Primordial (Auran)
CR 10 (XP 5,900; PB +4)
Air Form. The elemental can enter a creature's space and stop there. It can move through a space as narrow as 1 inch without expending extra movement to do so.
Iron Scent. The elemental can pinpoint the location of ferrous metal within 60 feet of itself.
Poisonous Air. Constitution Saving Throw: DC 16, any creature that starts its turn inside the space of the elemental. Failure: The target becomes poisoned until the start of its next turn.
Unusual Nature. The elemental doesn't require air, food, drink, or sleep.
ACTIONS
Multiattack. The elemental makes two Corroding Slam attacks.
Corroding Slam. Melee Weapon Attack: +9, reach 5 ft. Hit: 32 (5d10 + 5) acid damage. Miss - Dexterity Saving Throw: DC 16. Failure: A metallic nonmagical armor or shield takes a -1 penalty to the AC it offers (armor). Armor is destroyed if the penalty reduces its AC to 10. The penalty can be removed by casting the Mending spell on the armor or weapon.
Oxidizing Whirlwind (Recharge 5-6). Constitution Saving Throw: DC 14, each creature in a 30-foot cone. Failure: 32 (5d12) bludgeoning damage. Nonmagical metallic objects that affected creatures are wearing or carrying take a -1 penalty to the AC they offer (armor) or to their attack rolls (weapon). Armor is destroyed if the penalty reduces its AC to 10, and a weapon is destroyed if its penalty reaches -5. The penalty can be removed by casting the Mending spell on the armor or weapon.
QUICK REFERENCE
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.