Definition
Physeter is the genus that includes the sperm whale (*Physeter macrocephalus*). Sperm whales are the largest toothed predators in the world, known for their massive heads and deep-diving abilities. They are part of the Physeteridae family. Physeter whales hunt squid and fish in the deep ocean. Think of *Physeter* as the 'surname' for sperm whales, like the 'Smith' in John Smith. It designates the sperm whale's place within the broader animal kingdom.