text: where do sperm whales get there name from?   the sperm whale (physeter macrocephalus) is the largest of the toothed whales and is believed to be the largest toothed animal to ever inhabit the planet. (the baleen blue whale is larger, and invertebrates such as the lion's mane jelly fish or the portuguese man of war may be longer.) the whale was named after the milky-white substance spermaceti found in its head and originally mistaken for sperm. the sperm whale's enormous head and distinctive shape, as well as its central role in herman melville's moby-dick, have led many to describe it as the archetypal whale. partly due to melville, the sperm whale is commonly associated with the mythological leviathan of biblical lore.  historically the sperm whale has also been known as the common cachalot. the word cachalot is originally portuguese (cachalote), probably coming from cachola, a colloquial term for head. sperm whales were hunted until recently in the portuguese atlantic archipelago of azores.