or cachalot
Thickset, blunt-snouted toothed whale ( Physeter catodon , family Physeteridae) with small, paddlelike flippers and rounded humps on the back.
Sperm whales have an enormous head, squarish in profile, and a narrow, underslung lower jaw with large conical teeth that fit into sockets in the toothless upper jaw when the mouth is closed. They are dark blue-gray or brownish. ( ambergris . The pygmy sperm whale (genus Kogia ) is a black dolphinlike whale, about 13 ft (4 m) long, of the Northern Hemisphere that lacks commercial value.