Not all Leviathans rely on brute force. There are exceptions. Selkie is one of those exceptions. Instead of growing larger, as the water allowed, Selkie's size remained close to those of her ancestors. In dim light, Selkie might even be passable as a normal Pearlcatcher with a beautiful singing voice. As soon as anyone comes closer, wether it be a dragon infatuated by her voice, or a predator thinking they'd found an easy target, that's when her real assets come to play. Razorsharp teeth and a clad skin make her the equivalent of a piranha in both speed and hazard. Any target gripped between her teeth won't see the surface ever again.