Gray whales are often covered with parasites and other organisms that make their snouts and backs look like a crusty ocean rock.
The whale uses its snout to forage by dislodging tiny creatures from the seafloor. It then filters these morsels with its baleen—a comblike strainer of plates in the upper jaw. A piece of gray whale baleen, also called whalebone, is about 18 inches (46 centimeters) long and has a consistency much like a fingernail. Whalebone was once used to make ladies' corsets and umbrella ribs.
The gray whale is one of the animal kingdom's great migrators. Traveling in groups called pods, some of these giants swim 12,430 miles (20,000 kilometers) round-trip from their summer home in Alaskan waters to the warmer waters off the Mexican coast. The whales winter and breed in the shallow southern waters and balmier climate. Other gray whales live in the seas near Korea.
Like all whales, gray whales surface to breathe, so migrating groups are often spotted from North America's west coast. These whales were once the target of extensive hunting, and by early in the 20th century they were in serious danger of extinction.
Today gray whales are protected by international law, and their numbers have grown. In 1994, the gray whale was removed from the United States endangered species list.
For more information go to - http://animals.nationalgeographic.com/animals/mammals/gray-whale/