Whisgalge are known to take control of entire kelp forests as their territory and chase off anyone who enters with their corrosive poison. A kelp forest shaking violently due to an earthquake is a telltale sign that a Whisgalge inhabits the area.
Their poison is strong enough to eat through the hull of a tanker, and they spit it indiscriminately at anything that enters their territory. Mysteriously, it can foretell earthquakes.