Low
The overwhelming majority of life on Earth. Harmless to humans, and frequently far more interesting for it.
Carolina Wolf Spider
A web-free night hunter that grinds up frogs and carries its babies on its back.
Casper Octopus
The nearly translucent deep-sea octopod that nobody has named, because nobody has ever caught one.
Central Bearded Dragon
The sun-loving outback lizard that bluffs with a puffed-out beard and waves an arm to back down.
Chambered Nautilus
A shell that works like a submarine's ballast tank, an eye with no lens, and a sense of smell that can follow a scent up to 10 meters in the dark.
Channel Catfish
A catfish called a swimming tongue, with taste buds all over its body to find food in murky water.
Chicken
The toothless bird whose gizzard does the chewing, whose hen usually lays an egg every 26 hours, and which outnumbers every other bird species.
Chilean Rose Tarantula
The desert tarantula with no extensor muscles at two leg joints, and a metabolism that slows when food runs short.
Chinstrap Penguin
The seabird that nods off more than 10,000 times a day in naps that average four seconds, banking over 11 hours of sleep in each half of its brain while it guards the nest.
Coelacanth
Thought to have gone extinct over 65 million years ago, then found alive in 1938, with fleshy fins that move like a four-legged animal's legs and a pregnancy of around five years, possibly the longest of any vertebrate.
Colossal Squid
The heaviest invertebrate documented, with tentacle hooks that swivel up to 720 degrees and eyes about the size of a soccer ball.
Comb Jelly
The predator that pulses with rainbow diffraction along its beating ciliary comb rows, and not one flicker of it is bioluminescence.
Common Blackbird
A lawn-hopping songster whose night-time hormones shift under city light.
Common Cuckoo
A brood parasite whose females lay eggs that tend to match their hosts' eggs.
Common Cuttlefish
A color-blind ocean shapeshifter that reads polarized light and turns its skin from smooth to spiked in moments.
Common Earthworm
A hermaphrodite that lives in deep vertical burrows and generally leaves them only to feed and mate.
Common Earwig
The garden insect whose mother grooms her eggs like a hen and may go as long as 7 months without feeding.
Common Eastern Firefly
A beetle whose males trace a J of light at dusk and bleed defensive steroids when attacked.
Common Frog
The frog that lives as far north as the Arctic Circle and sits out winter under rocks or buried in pond mud.
Common Garter Snake
A North American snake, some of whose populations have evolved resistance to the toxin of the newts they eat.
Common Goldfish
The pond fish that makes alcohol to survive without oxygen and sees four colors, ultraviolet included.
Common Hermit Crab
A scavenger that lives in an empty sea snail shell and raps on rivals' shells to try to take over better ones.
Common Kingfisher
Electric-cobalt torpedo diver, riverbank jewel, and an underwater strike made by touch alone.
Common Loon
A dagger-billed diver with dense bones, a wolf-like wail and legs set too far back to walk well.
Common Octopus
A shallow-water hunter whose colour-changing skin is run by over half a million neurons, yet which is estimated to live one to two years.