Dhelgalge is a terrifying creature that dwells in the ocean depths and devours everything it encounters. If a ship sails through its territory, it surfaces and uses its anchor-shaped fins to drag the vessel down into the abyss.
Their poison is strong enough to eat through the hull of a tanker, and they spit it indiscriminately at anything that enters their territory. The soul of seaweed adrift in the waves became reborn as this Pokémon.