Rust Strider (5e Creature)
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Large aberration, neutral
Saving Throws Str +4,Dex +2, Con +4
Shell Up. Rust Strider can pull the plates of its legs and abdomen together to create an armored barrier. Initial damage for rust strider and its rider is reduced by half.
Scrap Metal Diet. Any metal worth 5cp can be consumed by a rust strider as food for the day. (This includes coins.)
Bite Attack. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 1 piercing damage
Metal Slurp. Melee Touch Attack: +3 to hit, reach 5 ft., one target. The rust strider corrodes a nonmagical ferrous metal object. The bite destroys a 1-foot cube of it. If the object touched is either metal armor or a metal shield being worn or carried, its takes a permanent and cumulative -1 penalty to the AC it offers. Armor reduced to an AC of 10 or a shield that drops to a +0 bonus is destroyed. If the object touched is a held metal weapon, the weapon takes a permanent and cumulative -1 penalty to damage rolls. If its penalty drops to -5, the weapon is destroyed. Non magical ammunition made of metal that hits the rust monster is destroyed after dealing damage.
The rust strider is a mysterious insectoid creature of metal held together by seamlessly integrated organic matter. Its dominant feature is six long legs each ending in massive curved plates infused with various metals. These plates act as the feet with a small plume of hair like setae at the end to attach to most surfaces. The legs attach to a narrow but sturdy thorax that supports a large diamond shaped abdomen of similar metal composites as the legs. The head is similar to most any insect but with only two black eyes. A small beak serves as a mouth, splitting open to reveal several feathery brushes it uses to break down and slurp up food.
The diet of the rust strider mostly consists mostly of metal with the occasional need to eat soft decaying flesh. The average person might confuse this insectoid creature to be a rust monster, but the rust strider has a much smaller appetite. What metals it does eat are broken down and used to strengthen the exoskeleton which becomes difficult for any predator to crack. The few who do manage to see the insides of this creature will find only lean muscular fibers and a network of tubes serving as its nervous system and veins. There are no complex organs let alone a brain.
The rust strider is a mindless creature. The behavior of it is that of a drone. It only responds to clicks and vibrations created in its tunnels by its immobile queen. They seek out food and use their hard bodies to deter predators from their nests. If need be the rust strider can pull itself into a ball to protect itself further, taking any eggs it can inside itself. Very few creatures find them worth eating, but smarter creatures have found a way to control the rust strider through tools that simulate the clicks of the queen.
Many races of the under dark have captured and trained these creatures to serve as mounts using a clicking gauntlet that can be felt by the rust striders tremor sense. Even in heated combat or magical silence a rider can guide their mount. Normally a rust strider egg sells for 200gp. A full grown rust strider sells for 600gp. Though most of the cost is to the command gauntlet. The rust strider can not be trained.