Sperm whale
Mature males average in length but some may reach , with the head representing up to one-third of the animal's length. Plunging to , it is the third deepest diving mammal, exceeded only by the southern elephant seal and Cuvier's beaked whale. The sperm whale uses echolocation and vocalization as loud as 230 decibels (re 1 µPa m) underwater. It has the largest brain on Earth, more than five times heavier than a human's. Sperm whales can live 70 years or more.