The sperm whale is also called cachalot is the largest whale with teeth and the largest predator with teeth. The mature whales can reach up to 52 feet and some can even reach 67 feet. This species of whale has a head that is one third of its length, and it mainly eats squid. Cuvier's beaked whale is the mammal that can dive the deepest, followed closely by the sperm whale. The sperm whales communicate through clicking vocalization with each other. They have the largest brain on the Planet and can live more than 60 years.