Pyrrhus

Pyrrhus lives deep underground and feeds mainly on coal. He doesn't mind minerals and metals as well but doesn't go out his way to seek them out. He can sense his food from miles away and digs through the ground to get to hidden coal seams. He's pretty useful to miners, since he doesn't usually stay for long at one place and leaves tunnels leading to previously hidden areas.

He loves the taste of human blood and meat. Gets high on the smell of human blood. When he's known to be around, people don't usually get down to the mine. Sometimes he gets back unnoticed and accidents happen. And those aren't always accidents. People prefer to keep his bloodthirst sated. That keeps him from coming out and hunting outside.

Imagine a group of people down in the mine. All the lights go out in a second and the air gets filled with choking smoke. They're trying to get back to the main shaft but there's something in their way. They can see the red glowy eyes and glowing scars. They can hear his ragged breath. And then he opens his mouth and lava spills out of it, pooling in front of him and illuminating his head and front paws. In that moment they all know they probably won't get out alive. It's not really about feeding. There's lots of food around. He just wants to taste and smell.