When the King Comes Knocking:Rust Monster

A rust monster is a creature that seeks out and consumes metal, often the armor and weaponry. It has a strange bacteria living in its stomach and blood stream that caused metal to rust. Rust monsters have poor sight, although their sense of smell for metal is extraordinary. Handheld spears are useless against its armor, although wooden clubs and crossbow bolts were effective. Rust monsters give birth to live young.