Ok so this skin is for the Biome Dependent Character skin contest!
The biome I chose was cave.

This is not any ordinary bat, it's a stone ore bat. It collects and wears ore all over itself. You can see the diamonds on the legs, the golden eye, the emerald on the back, the lapis on the back of the head, the copper shoulder piece, the iron wings, the coal on the shoulder, and the redstone ears. Fire on the bottom of the back of the legs shows that deep in caves, there is lava and fire. The stone bat's gray color comes from its stone diet. It eats all kinds of stones, ranging from diorite all the way to dripstone. This bat seems to have a mainly stone diet, with some diorite, which we can see from the left arm. Stone bats like to wear iron, as they like the shininess of it. Some stone bats will also wear gold. This one seems to have a gold gem on its left side torso. It also wears iron all over itself, mainly on the head.