I'm having fun over at Art Order again. We were to use the tiny, yet highly destructive Boll Weevil as inspiration:
The concept behind this critter is that he is a weapon and armor eating beast. These guys roam around searching for unsuspecting humans that just happen to carry their favorite food - metal. They use their long frontal dexterous appendages to seek out and procure edible material. Because of their size and strength, fighting back proves futile and the unfortunate humans are robbed of all armor and weapons. The beasts eat the objects, metabolizing the metal, which is then secreted as alloys to form a nearly impenetrable exoskeleton.