Some animals possess elemental bending powers. Their bending may be overt, as with creatures such as badgermoles which can be trivially observed to use earthbending, or subtle, as with the flying lemur, which uses airbending to fly when it would otherwise only be able to glide due to its limited upper body musculature.

Mythology describes various instances of humans learning bending from observation of bending animals, and indeed this is a motif in the legends of many peoples with a bending culture. Whatever the role bending animals may have played, the origins of human bending are lost in prehistory.

Waterbending Animals

Water Dragon

Water dragons are described in old records, and some purported skeletons exist. What became of them, and if there might be any left, is unknown.

Walrus Yak

The Walrus Yak is a naturally waterbending creature found in the cold parts of the Southern Sea. Its waterbending powerfully enhances its mobility.

Jungle Lemu

A monkey-like animal that is known for swinging on vines and building elaborate round nests out of vegetable matter, high in the jungle canopy (and often incorporating the branches of the living tree.) Researchers have found that they are natural waterbenders, believed to manipulate the water inside living plants. They have large ears and sensitive hearing, and a patagium. They are capable of gliding (usually between trees), but not flight. The Flying Lemur is similar-looking but unrelated, having actual bat-like wings rather than a patagium. They are found in the jungles of the Southern Earth Kingdom.

Earthbending Animals

Badgermole

The Badgermole is well-known. Domesticated varieties include dwarf badgermoles.

Stonecats

The stonecat is a meerkat-like colonial mammal which excavates extensive burrow complexes into solid stone with its natural earthbending.

Armadillodog

Armadillo-dogs are earthbending animals which carry around a stone shell with them. It is not part of the animal, but rather constructed with its natural earthbending. When threatened, they withdraw into the shell and seal it around them perfectly except for a labyrinthine airhole, anchoring themselves to solid rock if available.

Olgoi-Khorkhoi worm-snake

A natural sandbender, the venomous worm-snake of the Hanwang desert conceals itself in the sand and uses its sandbending to suddenly make sand loose beneath prey, which it then bites underground. It is said that it can move through sand faster than a man can run.

Firebending Animals

(Fire) Dragon

The Dragon was the natural firebender par excellence. They are believed to have been hunted to extinction.

Qilin

The Qilin is another firebending animal, a scaled quadruped outwardly similar to a horse, but with a single horn. They are very rare, but their existence is scientifically accepted. They are solitary creatures which are long-lived. Their appearance is said to portend the birth or death of great sages.

Smoke Leopards

The Smoke Leopard is a firebending pack hunter, which uses its natural fire to set and control wildfires, flushing prey out and trapping it to be devoured. They are indigenous to the Fire Islands, but were imported to other lands during the Fire Nation invasion, as hunting Smoke Leopards is a culturally significant activity for many Fire Nationals. Stable wild populations have established themselves in the Southern and Western Earth Kingdom, radiating outward from Fire Nation colonies. The are sociable and surprisingly even-tempered when tamed, but obviously quite dangerous and only rarely kept as pets.

Airbending Animals

Flying Lemur

See Flying Lemur, a subtle bender which enhances its aerial performance with natural airbending.

Flying Bison

The Sky Bison figured prominently in the development of the Air Nomad culture, being the principle animal herded by airbending nomads. They were once widely used as a means of transport, though they can be temperamental (especially toward non-airbenders) and so the industry of transport with flying bison was dominated by Air Nomads. Because of their foundational role in the economy of the Air Nomads, and important cultural role, the Fire Nation targeted the species during the Air Nomad genocide. They employed methods such as shooting them down wherever they were directly encountered, exterminating them with poison baits after burning their grazing lands, and ruining the mountainous valleys of the Air Nation in which they gathered seasonally to calve. Accordingly, the animals are very rare today, though occasional sightings are reported.

Others

Lion Turtle

Huge city-sized creatures, which may actually be spirits, they were noted to be able to give and take bending ability from humans.