Thermalgae

Splitting from its ancestor, the thermalgae has taken to living deeper within Mae Sandstone Caverns and now inhabits the Magma Caverns deep within them. To adapt to this world of extreme heat, the thermalgae now thrives on high temperatures. Unable to survive without the extreme heat, its body becomes stronger as the heat rises. The various elements that it "eats" are used to strengthen its structure and give it form, and when they die it is released back into its surroundings. These elements actually compose most of its body makeup. Forming thick crusts on all available solid surfaces, they can occasionally be found a few inches above the magma's surface.