Rust Monster

A rust monster is a fictional creature from the Dungeons & Dragons fantasy role-playing game that seeks out and consumes metal, often the armor and weaponry of players' characters. Originally inspired by a cheap plastic toy, the rust monster was one of the first monsters specifically created for D&D, and has been included in every edition of D&D, although various aspects of the creature have changed from edition to edition. Although in most editions, the rust monster has been a non-lethal creature with little or no way of physically harming players' characters, it is the rust monster's ability to destroy a character's cherished and expensive weapons and armor in mere seconds that makes it a particularly fearsome opponent.