Leviathan Durability

Leviathan, nonstandard cardiac, nervous systems: irregular biology. No standard organs or weak points. No brain, heart or center of operations for rest of his body. Irregular biology, no vulnerable organs: body divided into layers, extending down to hyperdurable core body, each layer down is slightly more than twice as durable as previous.

Exterior skin is hard as aluminum alloy, but flexible, lets him move. 3% deeper in toward core of arms, legs, claws, tail, or .5% in toward core of head, trunk, neck, tissues are hard as steel. 6% in toward core of extremities or 1% toward core of main body/head, tissues strong as tungsten. 9% toward core of extremities, 1.5% toward core of main body, head, tissues strong as boron. 12%-