ok apparently this got disqualified from the Miners and Cave dwellers contest so let me explain.

She's a human-like creature who's skin is made from stone. She lives near the bedrock layer and waits for innocent miners to come by and attacks. The bones in her arm are exposed because while fighting a particularly strong miner she had gotten lava splashed at her and dodged at just the right moment so that only her left arm was hit. Legend says that whoever can kill her will be blessed with great riches and honor.