Mantlecrabs are stone-based crustaceanous animals native to the planet Pyrovillia.
Mantlecrabs greatly resemble Earth's fiddler crabs, albeit ones the size of bulldogs and seemingly carved out of smooth black stone. They have no mouths, as they absorb energy directly from lava pools, but they do have three crystalline eyes each and an advanced sense of hearing.
There have been occasional sightings of giant Mantlecrabs, but other than an alleged preserved body of such a creature outside of a coffee shop on the Planet of the Coffee Shops, no physical evidence exists.
Mantlecrabs, almost like penguins, inhabit the shores of lava oceans on Pyrovillia, feeding off the heat. They have been observed crawling across the ocean bottoms to reach other continents. It is theorized that they possess a strong navigational sense, possibly one that relies on the detection of seismic activity.
Mantlecrabs have very little intelligence, and for the most part sit motionless in the shallow fluids of the lava oceans. However, certain times of the year, notably breeding season, mark a drastic change in behavior among Mantlecrab males, which begin to fling fireballs at one another and at any other entites which come close in a lethal display of firepower.