The rust bubblehorn split from the spikedshell bubblehorn. It lives among the rust weed and rust shrubs. It eats the dead plant matter from it and absorbs a lot of iron. This turns its shell and body a red-orange tint. Like its ancestor, it uses its bubblehorn sensory organ to find decaying food. It helps enrich the soil much like Earth's earthworms. Its tube-like mouth and legs are retractable and can go back into its hard spiky shell. It is heavier than its ancestor, even though it's the same size, due to the iron it absorbs. This actually strengthens its shell.