Found at the bottom the deepest reaches, trenches, and pits (like the one deep below the initial crash site), light itself seems to disappear from the world as this creature approaches. It has developed a unique hunting ability, releasing a chemical that when mixed with the heavy metals in the water turns the environment pitch black as it absorbs every bit of light. Then it uses a form of sonar with its growl, simultaneously intimidating and detecting the exact location of its prey caught within the darkness.