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
Creature Features the 1970s, the films of Amicus Productions and Tigon British Film Productions, which included "Dr. Terror's House of Horrors" and "The House That Dripped Blood", became popular features on the shows. "Creature Features" also aired many "nuclear monster" and "space alien" science fiction movies. Created in the 1950s, these movies generally featured giant mutant monsters or aliens from outer space terrorizing Earth. These included "Attack of the 50 Foot Woman", "The Amazing Colossal Man", "Them!", "Tarantula", "The Thing from Another World", "It Came from Outer Space", "The War of the Worlds", and "Forbidden Planet". "Creature Features" usually aired on Friday