The sperm whale (Physeter macrocephalus) or cachalot /ˈkæʃəˌlɒt, ˈkæʃəˌloʊ/ is the largest of the toothed whales and the largest toothed predator. It is the Family: Physeteridae. Sperm whales or Physeter macrocephalus are part of the Odontoceti (toothed whales). The Sperm whale is the largest toothed mammal in the world! Like most odontocetes, the males are larger than the females. They can weigh up to , pounds and measure in at 20 meters.