This is another strong "maybe" to the question since genetic combinations as well as environmental conditions can vary wildly. This creature is like a modified sea slug. It would be very large and enormously strong, and behave like a caddis fly in that it collects and bonds rock and coral to itself and encourages live coral growth on it's massive back. If it's threatened, it can retreat into its "mountain", and it generally subsists in a symbiotic way with the fish that shelter in it's coral forest. If the slug itself or it's living coral is threatened by other more predatory creatures, it can simply glide away to a more secure environment.

Mara