Rust MonsterMedium beast
Iron Scent. The rust monster can pinpoint, by scent, the location of ferrous metal within 10 meters of it.
Maneuvers. The rust monster uses maneuvers (maneuver save Difficulty 11). It has 2 stamina dice which are d8s, a dice limit of 1, regains all expended stamina dice when it finishes a long rest, and regains half its total stamina dice when it finishes a short rest. It knows the following maneuvers:
Rust Metal. Any nonmagical weapon made of metal that hits the rust monster corrodes. After dealing damage, the weapon is permanently corroded 1. Nonmagical ammunition made of metal that hits the rust monster is destroyed after dealing damage.
Bite. Melee Weapon Attack: +2 to hit. Hit: 5 (1d8 + 1) piercing damage plus 4 (1d8) acid damage and the target’s armor or natural armor is corroded 1 until the end of the rust monster’s next turn.
Antennae. The rust monster corrodes a nonmagical ferrous metal object it can see within 1 meter of it. If the object isn’t being worn or carried, the touch destroys a 30-centimeter cube of it. If the object is being worn or carried by a creature, the creature can make a Difficulty 11 Reflex saving throw to avoid the rust monster’s touch.
If the object touched is either a held metal weapon, metal armor, or a metal shield being worn or carried, it is permanently corroded 1.
As an action, you can use the Dash action. If you move at least 3 meters straight toward a creature, you can make a melee weapon attack against it.
On a hit, add the stamina die to the attack’s damage.
On a critical hit, add twice as much damage.
On a miss by 4 or less, add half as much damage.
You can increase the damage for each additional stamina die expended.