Phanta-Rays

Since the only hostile mobs in the ocean are drowneds and guardians, perhaps. . . THE PHANTA-RAY! This mob is like a phantom, but underwater. It would be INCREDIBLY fast, and would only come out at night, and would retreat to their dens during the day. Phanta-Rays would drop phantom membranes, as well as an extremely rare chance to drop a fin. Combining two fins with an elytra would make water wings, which function as an elytra, but underwater, allowing for players to travel at high speeds underwater. Please feel free to leave any suggestions that you may have.