Crystal Cavedweller

Cavedwellers can vary dramatically in their looks, depending on the type of cave they inhabit. Their diets can range from small mammals to minerals found in groundwater, according to what is readily available in their environment. All of them are fiercely protective of their turf and will attack intruders. While many of them seem very intelligent, no one yet had been able to get close enough to one to befriend it.
This particular specimen lives in a cave with no large opening to the surface. Within, a vast network of columns formed and tiny microscopic organisms attached themselves to it. Even in death, their shells give off beautiful shades of blue and green for a few months. Several times a year, the entire cave will flood, bathing everything in anther layer of organisms, replenishing the light. The cavedweller absorbs the energy from the light in some bizzare process that involves the outgrowth on it's back. It's arms and insectoid legs growing from it's back help it climb around the sharp rocks. It is blind, but appears to be to able to sense the surroundings.
Nothing else is known. It could be millennia old, or somehow clones itself. It is also unsure why it looks like a canid, or how it even got there in the first place.

Made for this contest: [link]