In the cavernous hollows below the surface nest a species of gargantuan mollusks known as the kakikaiju. Spending the majority of their time in a sort of hibernation stasis, they often become covered with stalagmites and moss, making them difficult for the uninitiated spelunker to detect. When they sense a large life form nearby, they lash out with their mucous-covered "tongue", pulling their prey into the clutches of their granite-like shell.
Saving all of their energy for hunting allows the kakikaiju to perform lightning-quick, powerful strikes against their targets. Woe be unto the brave soul who dares to hunt them, but still, the payoff proves, time and time again, too much temptation for some to resist.
Kakikaiju pearl is one of the most sought-after crafting materials for both Cogs-folk and Necronauts, alike, being valued for both its beauty and its strength. These pearls typically range in size from 50-600mm in diameter, with the largest on record measuring in at 837mm, and come in a variety of colors. The rarest variety is the violet kakikaiju pearl which reflects a shimmering purple hue with deep black undertones, and is known only to be found beneath the Shadowlands.
Kakikaiju pearl was featured in numerous props and costume pieces throughout the series, most notably in the mask of Captain Gilliweed whose mask was carved entirely from a single piece of violet pearl.