Herbivore
Feeding exclusively on vegetation, relying on specialized microbial fermentation to break down tough plant cellulose.
Clydesdale Horse
A Scottish farm horse first bred in the mid-1700s for heavy hauling, with males standing up to 19 hands on feathered ankles.
Cockatiel
A small crested parrot from Australia's open country that can sing a human melody in near-perfect sync.
Coypu
A webbed-footed marsh rodent with its eyes, ears and nostrils on top of its head.
Desert Locust
A shy loner that turns into a swarming crop-eater when it gets crowded.
Domestic Rabbit
Sees almost all the way around, twists in midair when happy, and eats its own droppings for a second pass at its food.
Domestic Yak
Oversized heart and lungs, a shaggy coat and a home up to 5,000 m high.
Donkey
A working equid whose hee-haw can travel up to 3 km, domesticated in Africa around 5000 BCE.
Dromedary
The desert animal that lets its body warm to 41.7 degrees Celsius instead of sweating as the day heats up.
Dugong
A sea cow that rips up seagrass with a flexible upper lip and may live more than 50 years.
Elk
A bull's bugle is two sounds at once, and his antlers regrow every year at up to two-thirds of an inch a day.
Eurasian Beaver
Europe's orange-toothed dam builder, hunted to near extinction, then counted at over 1.5 million across Europe by 2012.
European Hare
Mom parks her furry newborns apart and makes the rounds to nurse them.
Garden Snail
A night-feeding garden snail that seals itself shut to wait out hot, dry weather.
Gaur
The largest living wild cattle, whose herds, one warden wrote, are prepared to stand and fight a tiger rather than run.
Gelada
The Ethiopian highland monkey that grazes mainly on grass, flashes a bleeding-heart chest patch, and rolls its lip back to bare its gums in a facial display no other primate can make.
Gerenuk
A bipedal antelope of Africa's dry thornbush that rears onto its hind legs to reach leaves other antelope can't, and does not drink standing water, relying instead on the succulent plants it eats.
Giant Panda
A carnivore-like gut, the strongest jaws of any bear, and a bony spare thumb, all pressed into a diet that's about 99% bamboo.
Giant Prickly Stick Insect
A leaf-mimic that sways like a branch in the breeze, and hatches looking like an ant.
Giraffe
Bulls can top eighteen feet, with a roughly twenty-five-pound heart built to fight gravity and an eighteen-inch tongue that dodges acacia thorns.
Goat
A domesticated ruminant with rectangular pupils and a digestive system that works nonstop.
Golden Snub-Nosed Monkey
Narrows the blood vessels in its skin to cut heat loss, then burns 14 percent of its body mass getting through a winter in China's mountains.
Green Iguana
A tree-top lizard with a light sensor on top of its skull that meters the sun and spots predator shadows from above.
Green Sea Turtle
The only sea turtle that is mainly a plant-eater, with a map in its head that is at least partly magnetic.
Groundhog
The largest marmot in its range, a tunnelling rodent that sleeps through the winter and warns its neighbours with a shrill whistle.