Yup, Hylas is right, that's "Puchiko" or more known, Petit Charat from the "anime" Di Gi Charat. This wallpaper is adorable, Fortune! I really like it!
*Side Note*
Di Gi Charat has the most adorablest looking characters, but BEWARE.....the "anime" is slightly annoying. Each episodes of the series are about 2-3 minutes long, and I'm not sure how many episodes there are though. I got a VHS tape that contains 16 episodes in 1 tape (yeah, they're THAT short), but I couldn't even get through watching the first episode, because it was slightly irritating.
Di Gi Charat's voice was really not what I expected, even in Japanese, and the story is kinda....confusing and pointless. But, the drawings are so adorable, that you can't resist, even if the anime is not so good. Well, that's just my opinion, anyone else can watch it and try to get through but....I know I'm never going to watch this series ever again. I'll continue looking at the cute pictures though.