Creatures for this Module:

The undergound lair is no regular dungeon, and the creatures within are also abnormal in many ways. The bizarre experiments of Ancient Wizards have magically warped the dwellers within the halls. For this module the creatures inside the dungeon have these alternate characteristics… I have included the original statistics for reference as well.

Trained Rust Monster

Base Creature: https://5e.d20srd.org/srd/monsters/rustMonster.htm

Armor class 15 (natural armor & Larger shell plates)

Hit points 27 (5d8 + 5) [The Monster in A10 has Max HP = 45]

Speed 40 ft.

STR         DEX        CON       INT         WIS        CHA

13(+1)   12(+1)   13(+1)   2(-4)      13(+1)   6(-2)

Senses Darkvision 60 ft., passive Perception 11

Languages —

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 a permanent and cumulative −2 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.

Bigger: This particular Rust Monster is Large Size.

Actions

Multiattack: The trained Rust Monster may make two attacks, 1 Bite and 1 with its Antennae

Bite. Melee weapon attack: +3 to hit, reach 5 ft., one target. Hit: 5 (1d12 + 1) piercing damage.

Antennae.

The rust monster corrodes a nonmagical ferrous metal object it can see within 5 feet of it. If the object isn’t being worn or carried, the touch destroys a 1-foot cube of it. If the object is being worn or carried by a creature, the creature can make a DC 12 Dexterity saving throw to avoid the rust monster’s touch. If the object touched is either metal armor or a metal shield being worn or carried, it takes a permanent and cumulative −2 penalty to the AC it offers.

Armor reduced to an AC of 10 or a shield that drops to a +0 bonus is destroyed. If the object touched is a held metal weapon, it rusts as described in the Rust Metal trait.

Key Areas: A1 -/- A2 -/- A3 -/- A4 -/- A5 -/- A6 -/- A7 -/- A8 -/- A9 -/- A10 -/- A11 -/- A12 -/- A13 -/- A14