AIR

The most peaceful bending artists, the air nomads, unfortunately received the least peaceful fate,
being victims of the Air Nomad Genocide. In this massacre, the Fire Nation killed every airbender
and non-bending air nomad in the world - except one. Along with this single survivor, two others
managed to escape the wrath of the Fire Nation: Appa the flying bison, and Momo the winged lemur.
Behold, some pure scientific facts that separate Appa and Momo from the bison and lemurs we know today:

Bison		Lemur
Common Bison	Appa	Common Lemur	Momo

Ground dweller	Can fly!	Tree dweller	Can also fly!
500-1000 kg	10 tons???	Terrifying, yellow eyes that can see into your soul	Super cute green eyes
Four legs	Six legs	Five toes per paw	Four toes per paw
The kind of tail you would expect from a bison	Superior mega beaver tail	The kind of ears you would expect from a lemur	Superior mega ears
Does not respond to "yip yip"	Responds to "yip yip"	Does not respond to "yip yip"	Does not respond to "yip yip"