Sperm whales are the largest toothed whales on earth. Males are usually much larger than the females. The head in particular is enormous, accounting for one third of the entire body. The lower jaw, on the other hand, is remarkably small. Sperm whales eat giant squid, which live at great depths. Therefore, it's no wonder that these whales are specialists in deep diving. The record stands at a depth of 2800 meters.