Corghoula

In a rupture of salt water the Corghoula bursts from the tide, it's short peg-like legs bounding up the sand to tear into any beached Raukas (https://www.artstation.com/artwork/rRYzd6) or any other slow moving creatures that it senses with the heat pits along its sharpened snout. Tendrils rimming the chitin hard mouth numb the limbs of any defending prey as it rips and tears anything it can get into its jaw. Once it's torn great gobs of flesh from its attack it will slowly settle back into the sands beneath the tidal flats, sifting nutrients through the water like any other calm tempered mollusk, while it feeds off a great sphere of meat and bone for weeks at a time. In rare cases the Corghoula will produce a pearl of bone from the remains of many successful attacks, when threatened it will launch the single bone pearl with a spasm of it's internal muscles, akin to a cannon ball in its force.