Dolphins need about eight hours of sleep a day, but, unlike us, their brain sleeps in shifts. The right half gets four hours of sleep and the left half also gets four hours of sleep, just at different times.
Bullfrogs don't need sleep, as they don't have a sleep-wake cycle. Instead, they enter a state of dormancy, which is a period of inactivity and lowered metabolism. They can do this during the day or night, depending on the temperature and humidity.
Giraffes sleep less than any other mammal in the wild. They can survive and get energized with an average of just half an hour of sleep per day. With 24 hours per day, 30 minutes of sleep is nothing
Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant.
The horse is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of Equus ferus.
The great frigatebird is a large seabird in the frigatebird family. There are major nesting populations in the tropical Pacific Ocean, such as Hawaii and the Galápagos Islands; in the Indian Ocean
The giraffe is a large African hoofed mammal belonging to the genus Giraffa. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes have been thought of as one species, Giraffa camelopardalis, with nine subspecies.
The walrus is a large pinniped marine mammal with discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only extant species in the family Odobenidae and genus Odobenus.