According to Guinness World Records, which shark species has the thickest skin of any animal?

The whale shark isn't only the largest fish in the oceans. It also has the thickest skin of any living creature - in the oceans or on land. Typically around 10 cm (4 in) in thickness, the skin offers vital protection and insulation for the animal. The thick epidermis has the consistency of rubber is an evolutionary development that limits predators of this beautiful animal to killer whales, great white sharks, tiger sharks and humans.