Actions

Gore. Melee weapon attack: +8 to hit, reach 5 ft, one creature. Hit: 18 (3d8+5) piercing damage   Corroding Antennae. The rust monster corrodes a nonmagical metal object it can see within 5 feet of it. If the object isn’t being worn or carried, it destroys a 1-foot cube of it. If the object is worn or carried by a creature, the creature can make a DC 14 Dexterity saving throw to avoid the rust monster’s touch. If the object touched is either a metal weapon or a metal armor being worn or carried, it takes a permanent and cumulative −1 penalty to the AC it offers or to damage rolls. If a weapon’s penalty drops to −5, it is destroyed. Armor reduced to an AC of 10 or a shield that drops to a +0 bonus is destroyed.