Giant clam

Giant clams were one of the products of Davros' early experiments. They were kept under the Kaled Dome in a cave leading out to the wastelands. The Fourth Doctor said that its bite had the force to crush bone. (TV: Genesis of the Daleks)A giant clam bites Harry's leg as he and The Fourth Doctor are exploring the caves under the Kaled Dome, The Doctor subdues it by smacking it with a rock.