Sperm whale has the largest brain on Earth, more than five times heavier than a human's. Sperm whales can live for more than 60 years. Spermaceti (sperm oil), from which the whale derives its name, was a prime target of the whaling industry, and was sought after for use in oil lamps, lubricants, and candles. Ambergris, a solid waxy waste product sometimes present in its digestive system, is still highly valued as a fixative in perfumes, among other uses. Beachcombers look out for ambergris as flotsam. Sperm whaling was a major industry in the nineteenth century, immortalised in the novel "Moby Dick".
Blue whale penis immature categorized whale was and the smallest penis of a mature whale was . By comparison the average blue whale penis is nearly 3 times the size of that of a sei whale. Specimen measurements indicate that a blue whale measuring in length had a vestigial mammary slit of width and length, with a penis measurement of . In another specimen in which the length of the whale was and weighed 50.9 metric tons, the brain weighed only . The Icelandic Phallological Museum has a portion of a blue whale's penis measuring long and weighing , which "Iceland Review" has