Erm, first of all I am not making a square because I like peoples sigs to be of reasonable size, so for it to be square it would be rather small (twice the length/height of your mario avatar at the biggest ...say 400 pixels)
second of all I don't watch the show, so I know of Aang (guy with the blue arrow on his head and the flying thing) but not of the other characters.
thirdly I am going off my laptop for a while now... but if you still want me to make it then I will (though you will need to tell me which the other characters are... wait, I just googled them so that's ok)
also it would look better as a long rectangle for a sig, but I think I could compose it similarly to the square version you described.
I will send it tomorrow if you say yes (of course other people may offer between then and now)
