Karkadillos are ornery predators the size and shape of Ancient compact automobiles. Three "fins" jut from their bony shells, and a fourth protrudes from their pointed heads. Their tails end in studded, spiked masses.
Slow and ponderous, karkadillos primarily burrow after prey they can catch (giant worms, grubs, and the like), but they also ambush convenient topside prey by exploding forth with slashing claws and snapping jaws. And while too heavy to swim, their gills allow them to trundle along the beds of both fresh and saltwater bodies to devour giant crustaceans and mollusks.
Natural enemies, karkadillos and molebears fight to the death when one crosses the other's territory. These subterranean battles often create small localized tremors.
Mutations: Aberrant Form (Gills and Lungs), Increased Sense (Smell), Unique Sense (Vibrations)