Toothed whale brain size with the expected brain size based on such allometric analysis provides an encephalisation quotient that can be used as another indication of animal intelligence. Sperm whales have the largest brain mass of any animal on earth, averaging and in mature males, in comparison to the average human brain which averages in mature males. The brain to body mass ratio in some odontocetes, such as belugas and narwhals, is second only to humans. Dolphins are known to engage in complex play behaviour, which includes such things as producing stable underwater toroidal air-core vortex rings or "bubble rings". Two main
Cuvier's beaked whale another that had stranded itself at Aresquiès, Hérault, in May of the same year, and found the two to be identical. There is no connection between Cuvier's beaked whale and the mythical Ziphius, or "Water-Owl", a creature in medieval folklore which had the characteristics of both an owl and a fish. Its dorsal fin was said to be sword-shaped, and pierced ship's hulls, while the beak was said to resemble an owl's head. The body of Cuvier's beaked whale is robust and cigar-shaped, similar to those of other beaked whales, and can be difficult to distinguish from many of the