Rust Monster

Aberration · 2 hexes · SM +0 Rust Monster (Enraged Eggplant; answers SRD 3.5, SRD 5.1)

A four-legged scavenger the size of a big hound and a good deal heavier than it looks, plated in dull chitin and steering by a pair of long feathery antennae. It smells worked metal across a room and wants nothing else in the world: a touch of those antennae reduces a blade or a breastplate to red flakes, which it then eats.

Attributes

ST10

DX13

IQ2

HT12

HP15

Will9

Per13

FP12

Basic Speed6.25

Basic Move8

Dodge8

DR3

Melee attacks

Usage	Level	Damage	Reach
Sharp TeethSharp Teeth (13): thrust 1d-3 cutting, Reach C.	13	thrust 1d-3 cutting	C
Rusting AntennaeRusting Antennae (13): The rust monster has specialized antennae that are not armored, but provide a normal sense of touch. The antennaes allow the creature to feel things one yard away and can be targeted at -6 (comparable to eye-stalks described on p. B34). In addition, the rust monster can touch a metal object with its antenna to deal it 5d corrosion damage. It can parry with its antennaes.	13	The rust monster has specialized antennae that are not armored, but provide a normal sense of touch. The antennaes allow the creature to feel things one yard away and can be targeted at -6 (comparable to eye-stalks described on p. B34). In addition, the rust monster can touch a metal object with its antenna to deal it 5d corrosion damage. It can parry with its antennaes	—

Traits (12)

• Detect Metal (Biological (Passive); Smell-Based, Reversed)
• Discriminatory Smell
• Extra Legs (Four Legs; Cannot Kick)
• Horizontal
• Infravision
• No Fine Manipulators
• Numb
• Peripheral Vision
• Reduced Consumption 3
• Restricted Diet (Rusted Metal)
• Sharp Teeth
• Wild Animal

Skills (1)

• 14Tracking

Notes

• GCS ancestry draft: gcs/rust-monster.gct
• Source template total: 15 points.
• Library-rebuilt template total: 15 points.
• CER was computed from parsed Typical Stats using the Dungeons On Automatic baseline CER path.
• Review attacks, special abilities, encounter frequency, treasure, grappling, and GCS modifiers before approval.
• Size 2 hexes; Weight 200 lbs.

Encounter rating

CER51

Offense42

Protection9

Threat tierstandard

Appearing1

Wandering3

Tags

• srd-3-5
• srd-5-1
• aberration

GCS v5 downloads

• ↓ Character sheet (.gcs)Open directly in GCS
• ↓ Ancestry template (.gct)Apply to any character

Where this one came from

Source record

Rust Monster

Source system

gurps_4e_fan_conversion / author_permission

Released under

cc_by_4_0

Conversion

0.2.0-reviewed

Review status

approved

Credit

Original GURPS conversion by Enraged Eggplant, from Monsters (May 11, 2024); adapted and republished with permission.

Description

Written by Dungeons on Automatic, released under cc_by_4_0

• GCS ancestry draft: gcs/rust-monster.gct
• Source template total: 15 points.
• Library-rebuilt template total: 15 points.
• CER was computed from parsed Typical Stats using the Dungeons On Automatic baseline CER path.
• CER recomputed from the reviewed Typical Stats through the canonical Dungeons on Automatic CER path: OR 42, PR 9, CER 51, threat tier standard.
• Conversion baseline reported OR 43, PR 9, CER 52 (tier standard). The reviewed values come from the consumer CER implementation, which rounds damage once after the damage-type multiplier and credits ranged accuracy; the conversion baseline ceilinged the damage base first and ignored range.
• Encounter metadata derived (solitary): average number appearing 1, wandering weight 3. Encounter metadata derived for 0.2.0 from the reviewed threat tier and creature class (appearing: minor 4 / standard 2 / major 1 / severe 1, forced to 1 for solitary classes — including swarms, which are a single multi-body creature — and raised to 6 for gregarious minor creatures; wandering weight: minor 4 / standard 3 / major 2 / severe 1). The fan-conversion source states no appearing-in-numbers or wandering values, so these are derived, not source mechanics.
• Lair, treasure, and grappling remain unpopulated in 0.2.0 by package policy: the authorized fan-conversion source states no lair, treasure, or grappling values, and review declines to invent them. See review/policy/0.2.0-empty-field-policy.md.
• Description text is original Dungeons on Automatic prose written from this record's own converted statistics and from the project's art direction for the creature. It is not derived from the authorized fan-conversion source, which states no creature descriptions, and not from any SRD. It carries its own authorship and CC BY 4.0 terms in the description field. See review/policy/description-policy.md.
• Review approved by automated-mechanical-review on 2026-07-26 (batch ee-2026-07-26-b5-cer-drift); GCS fidelity check passed, DOA playability check passed.
• The conversion baseline's published ratings disagreed with the consumer CER path; the reviewed ratings come from the consumer implementation and the difference is recorded in conversionNotes.