The badgermoles are powerful creatures that live underground who can naturally use earthbending. One of them breaks through a wall of the cavern, sending large boulders flying and shaking the ground.
The badgermoles use earthbending to trap Sokka and the wandering nomads (note they move their hands).
The earliest earthbenders (ignoring those who borrowed the power of bending from the lionturtles in pre-Avatar ages) originally learned bending from the badgermoles. According to legend, one of these first earthbenders (Oma) almost singlehandedly wiped out both sides of a war with her earthbending (which is how the city of Omashu was said to be founded).
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(From Book Two: Episode 2)
Badgermoles were the first earthbenders, using their bending to make tunnels and travel underground; they use the ground to 'see' as they are blind. A little know fact is that badgermoles love music, and using music one can control them.
After humans left the cities on the lionturtles backs, earthbenders learned to bend from the badgermoles.

The badgermoles use earthbending to trap Sokka and the wandering nomads (note they move their hands).

The earliest earthbenders (ignoring those who borrowed the power of bending from the lionturtles in pre-Avatar ages) originally learned bending from the badgermoles. According to legend, one of these first earthbenders (Oma) almost singlehandedly wiped out both sides of a war with her earthbending (which is how the city of Omashu was said to be founded).

The Cave of Two Lovers
Cave of Two Lovers Farming village Farming village hospital Omashu "The Cave of Two Lovers"
When the Badgermoles return underground, they close up the tunnels they came through.Aang: It must be the two lovers from the legend; that's who's buried here.
Katara: These pictures tell their story. They met on top of the mountain that divided their two villages... The villages were enemies, so they could not be together...but their love was strong and they found a way. The two lovers learned earthbending from the badgermoles; they became the first earthbenders. They built elaborate tunnels, so they could meet secretly. Anyone who tried to follow them would be forever in the labyrinth. But, one day, the man didn't come - he'd died in the war between the two villages. Devastated, the woman unleashed a terrible display of her earthbending power - she could have destroyed them all... But, instead, she declared the war over. Both villages helped her build a new city where they would live together in peace. The woman's name was Oma and the man's name was Shu. The great city was named Omashu as a monument to their love.

(From Book Two: Episode 2)
Badgermoles were the first earthbenders, using their bending to make tunnels and travel underground; they use the ground to 'see' as they are blind. A little know fact is that badgermoles love music, and using music one can control them.
(Originally from the Avatar Encyclopedia from the old Nickelodean website)Creature: Badgermoles
These giant animals are a cross between a badger and a mole. Badgermoles use Earthbending to make tunnels and travel underground, where they hunt for prey and live. Badgermoles were the first Earthbenders – they are blind but they use their Earthbending to feel the ground and “see”. A little known fact about the Badgermoles is their love for music – if the right music is played, you can get a badger mole to do just about anything.
After humans left the cities on the lionturtles backs, earthbenders learned to bend from the badgermoles.
(Avatar Legends: The Roleplaying Game, page 28)Certain people can manipulate one of four elements. This abilityis called bending, and its origins go back to when humans built cities on the backs of the lion-turtles thousands of years ago (page 16). After humans left the lion-turtle cities for good, legend says that they learned bending from animals like the earthbending badger-moles, firebending dragons, airbending sky bison, and in the case of Waterbenders, the spirits of the moon and ocean.