Disclaimer: Avatar: The Last Airbender is not owned by me. And believe me, you'd be able to tell if it was.
A/N - If while reading you can think of something better for any of the letters, please inform me. Some of them are just...wowzers.
A is for Aang
Aang is a short, bald kid who has problems with color coordination (see his outfit?) and also happens to be the Avatar. But he should really work on that color thing.
A is also for Azula
Has better color coordination than Aang, but happens to be an evil bitch. Huh. Oh, and I should probably mention that she's a princess and therefore has the power to USE her evil bitch-itude.
A is also for Appa
Why does everything in this show start with A? Appa is a flying bison. No-one can really TELL how he flies, but it appears that he flaps his tail around a lot to achieve liftoff. He ferries the Avatar and his merry band of losers around.
A is also for Air Nomads
Those hobos you see in the sky.
Oh, okay, they're the Airbenders (who blow at each other as a method of attack) and they're all dead (what a shocker).
B is for Ba Sing Se
An Earth Kingdom city where some nutty shit goes on.
B is also for Boomerang
Sokka's misused weapon which is more like a prop for a comedy routine.
C is for Cave of Two Lovers
An excuse for Aang and Katara to make out.
Also provides us with a funny song to sing.
D is for Dai Li
The crazed and disillusioned brainwashing organization lead by the guy with the Girly Braid of Doom.
E is for Earthbending
When people throw dirt at each other.
F is for Fire Nation
Who put a bee in their bonnet?
A fly in their soup?
A hair in their terriyaki chicken?
A cheese doodle in their anti-aging lotion?
G is for Grass
What Appa probably eats, and because I couldn't think of anything else for 'G'.
H is for Haru
An Earthbender who the Lame Brain Gang meets, greets, then rescues, all within the space of what seems like an hour.
I is for Iroh
The fat, tea-chugging uncle of his Emo Highness.
J is for Jet
A freedom fighter with terrible reasoning who constantly chews on a weed. Hint, hint, Nickelodeon?
K is for Katara
An annoying Waterbender who is comparable to Tea in Yu-Gi-Oh. See it? I do. She's also got some short, bald, un-color-coordinated kid fetish. Go figure.
L is for Lu Ten
The dead son of the fat tea-chugging guy. You have to wonder if he's better off taking the dirt nap...
M is for Momo
A lemur who is more intelligent than any of us think...
M is also for Mai
A very, very, VERY bored girl who won't stop expressing her boredom. She's friends with everyone's favorite psycho Firebender Azula.
N is for Nuts
What everyone in this show is.
Also what the Lame Brain Gang has to eat many a time (and they won't let us forget it...shut up already!)
O is for Ozai
Seems to need to attend parenting classes.
O is also for Omashu
An Earth Kingdom city where a crazed old king with some kind of unnamed disease rules.
P is for Prince
All of which are whiny and emo.
Q is for Quiet
What Sokka isn't but we wish he was.
What Zuko is when he isn't angsting.
R is for Roku
The former Avatar who needs a beard trim.
S is for Sokka
Katara's brother (pity him). He happens to be the lamest one in the group. The only thing he's good at is thinking of snappy nicknames. Also being a man-whore.
S is also for Suki
Member of the Organization Where We Paint Our Faces Like Clowns and Hit People With Fans (OWWPOFLCHPWF). One of Sokka's many loves.
T is for Toph
A little blind girl who can miraculously see through her feet. Question: Does she have eyes in her toes? And aren't they always getting dust in them?
T is also for Ty Lee
All bendy! An acrobat who pokes you a lot. She's friends with that nutty bitch Azula.
T is also for Tea
The drink that Iroh obsesses over and oddly enough is pretty important to the show. But it tastes really nasty. Ewww.
U is for Ugh
The sound everyone makes when Sokka opens his mouth.
V is for Violence
Lots of it, yet no-one ever bleeds. (...?)
W is for Water Tribe
The place, essentially made from ice and frozen dirt, where Katara and Sokka hail from. Go figure.
W is also for Waterbending
Equivalent to a squirt gun fight.
X is for Xylophone
No significance to Avatar, but it begins with 'X', so why the fudge not.
Y is for Yue
A disgustingly selfless girl with grandma hair who by some awkward miracle turned into the damn moon. Another one of Sokka the Man-Whore's many loves.
Z is for Zuko
His Emo Highness. Thinks that it's okay to angst all the time JUST BECAUSE he has a large, awkwardly shaped burn on his eye (why the hell is it his eye?) given to him by the former Whiny Prince who just HAD TO become Firelord. I guess it runs in the family.