Sperm whale
The sperm whale has a pale, waxy oil called spermaceti in its head. This allows it to dive up to 3,000 metres deep and remain under water for up to two hours.
The sperm whale has set several records. It is the largest toothed whale and has the biggest mouth of all whales. It could even swallow a person whole. However, it is not dangerous to people because it is only interested in attacking squid, of which it consumes around 1.5 tonnes a day. Its brain weighs 9.5 kilograms and is thus the heaviest of all mammals. It navigates through the seas using echolocation. You can hear it whistling, squeaking, and groaning under water from several kilometres away.
Fun fact
The sperm whale has a huge rectangular head, which accounts for one-third of its body length.
