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
Revenge of the Creature dismissive of the production. Although "Revenge of the Creature" has been broadcast on television in red-and-blue-glasses anaglyph form (e.g., in 1982 in the San Francisco Bay area), it was originally shown in theaters by the polarized light method and viewed through glasses with gray polarizing filters. A "flat" version without 3D was also released. In 1997, "Revenge of the Creature" was mocked on the comedy television series "Mystery Science Theater 3000", marking its first episode on the Sci-Fi Channel. Universal released "Revenge of the Creature" on DVD in a boxed set, along with "Creature from the Black Lagoon" and "The