Rust Monster

Most Dwarves would rather face a squad of Orcs than confront a single Rust Monster. These strange, normally docile creatures corrode ferrous metals, then gobble up the rust they create. In doing so, they have ruined the armour, shields, and weapons of countless adventurers.
A Rust Monster's body is covered in thick, lumpy armour, its long tail ends in a bony protrusion, and two feathery antennae sprout from its insectile head.

Underground Scavengers

Rust Monsters roam subterranean passages in search of ferrous metals such as iron, steel, adamantine, and mithral to consume. They ignore creatures not carrying such metals, but can become aggressive toward those bearing steel weapons and armour. A Rust Monster can smell its food at a distance, immediately dashing toward the scent's source to corrode and consume the object.
A Rust Monster doesn't care if the rust it consumes comes from a spike or sword. Adventurers can distract the creature by dropping ferrous objects behind them.

Subterranean Wanderers

Rust Monsters are rarely found in large numbers, preferring to hunt alone or in small groups. They meander along tunnels, moving from cave to cave in their tireless search for ferrous metals to consume. Their wanderings often bring them into contact with other Underdark denizens that find them harmless or unappetizing. Thus, Rust Monsters may be found in close proximity to other subterranean monsters. If they are well treated and well fed, they can also become friendly companions or pets.

Basic Information

Anatomy

A Rust Monster's body is covered in thick, lumpy armour, its long tail ends in a bony protrusion, and two feathery antennae sprout from its insectile head.

Ecology and Habitats

Subterranean Caverns, Dungeons and Ruins.

Dietary Needs and Habits

Ferrous Metal Objects

Additional Information

Social Structure

Loners or living in small groups of 3 to 6 creatures.

Domestication

Can be raised as pets and can be trained to guard areas if treated well and well fed.

Uses, Products & Exploitation

The Rust Monsters shell-like body can be used for armour or shields.

Facial characteristics

Insectile features, deep sunken eyes and a mandible jaw.

Geographic Origin and Distribution

The Underdark, Caverns, Dungeons and Ruins.

Perception and Sensory Capabilities

Darkvision 60ft & Passive Perception 11.

A Rust Monster by dndbeyond

Origin/Ancestry

Monstrosity

Lifespan

100 To 300 Years (Averaging 150 years old)

Average Length

Between 4ft and 9ft in length depending on age

Body Tint, Colouring and Marking

Varies from Reddish-Brown to Brownish-Black in colour.

"Destroyed me hammer and me axe, it did.Put me faith to the test that day,it did."
-Morin Thunderstone, Dwarven Paladin of Moradin 'The lord of the forge'

RUST MONSTER CR: 1/2 (100XP)

Medium monstrosity, unaligned

Armor Class: 14 (Natural Armour)

Hit Points: 27 (5D8+5)

Speed: 40ft

STR

13 +1

DEX

12 +1

CON

13 +1

INT

2 -4

WIS

13 +1

CHA

6 -2

Senses: Darkvision 60ft & Passive Perception 11

IRON SCENT

THE RUST MONSTER CAN PINPOINT, BY SCENT, THE LOCATION OF FERROUS METAL WITHIN 30 FEET OF IT.

RUST METAL

ANY NONMAGICAL WEAPON MADE OF METAL THAT HITS THE RUST MONSTER CORRODES. AFTER DEALING DAMAGE, THE WEAPON TAKES PERMANENT AND CUMALATIVE -1 PENALTY TO DAMAGE ROLLS. IF ITS PENALTY DROPS TO -5, THE WEAPON IS DESTROYED. NONMAGICAL AMMUNITION MADE OF METAL THAT HITS THE RUST MONSTER IS DESTROYED AFTER DEALING DAMAGE.

Actions

BITE:

MELEE WEAPON ATTACK: +3 TO HIT, REACH 5FT, ONE TARGET. HIT 5 (1D8+1) PIERCING DAMAGE.

ANTENNAE:

THE RUST MONSTER CORRODES A NONMAGICAL FERROUS METAL IT CAN SEE WITHIN 5 FEET OF IT. IF THE ISN’T BEING WORN OR CARRIED, THE TOUCH DESTROYS A 1-FOOT CUBE OF IT. IF THE IS BEING WORN OR CARRIED BY A CREATURE, THE CREATURE CAN MAKE A DC 11 DEXTERITY SAVING THROW TO AVOID THE RUST MONSTER’S TOUCH. IF THE TOUCHED IS EITHER METAL ARMOUR OR A METAL SHIELD BEING WORN OR CARRIED, IT TAKES PERMANENT DAMAGE AND CUMULATIVE -1 PENALTY TO THE AC IT OFFERS. ARMOUR REDUCED TO AN AC OF 10 OR A SHIELD THAT DROPS TO A +0 BONUS IS DESTROYED. IF THE TOUCHED IS A HELD METAL WEAPON, IT RUSTS AS DESCRIBED IN THE RUST METAL TRAIT.