Dragon

The dragons live on the hottest layer, the fire layer. It's constantly hissing from steam evaporating on its surface, and the environment is too hostile for any other beings.

Dragons are very calm creatures and spent most of their time sleeping in caves, far away from the heat, and bubbling of the ponds full of lava. As long as no one awakens them, they can sleep for decades, but when woken up abruptly they easily lose their temper.