You fell in a place all full of bones, then a shadow of a boney creature with 2 jaws as hands comes in

Good Heavens!, I'm sorry if I scared you. Let me introduce myself. My name is Clackula, Single Elemental of Bone (that's why there is a lot of bones). And welcome to Bone Island!, This is not a pit full of bones, this is an underground island, I was just preparing our buffett, but hey, you can be our special guest