Grampus griseus
Risso's are the most heavily scarred marine mammal on the planet — adults accumulate thousands of crisscross marks from the beaks and suckers of the Humboldt squid they hunt at depths beyond 1,000 feet, fading the skin from charcoal grey to near-white with age. Look for groups of 10–50 logging quietly at the surface off the Channel Islands, especially on calm October and November mornings.