@ Lili It's true that most people don't credit the artist when it comes to avatars. But if you want to you could always create a link through to either the avatar creator or the original artwork. When you do that personally I feel like if ever the artists happens upon your icon they'd be like 'oh they credited me'
But the chances of them seeing it is very low, especially if you only use it on this board and you upload it from your computer. Also, I'm pretty certain Hime-papa doesn't mind at all! So you could always use his official art.
@ Kiku And I would love to contribute to the avatar file, I collect Hetalia fanart like crazy I have over 1000 different drawings plus a 100 icons saved on my hardrive. (Not too mention all the doujins)
If you like, I can help you make some as well, I didn't draw my icon but I did tweak it a bit on photoshop. =3=