I'm not really happy with this, but I've found that's a recurring problem whenever I try to draw a character that really matters to me: I obsess, I still can't get it right, so I overwork it. (if I were working with regular old pencil and paper for example, I'd have erased a hole in the page.) The result isn't bad exactly, but it is overwrought, and it looses some of the natural grace of the original idea.
Oh, that's Agatha, by the way. She belongs to Phil & Kaja Foglio, and lives over at Girl Genius. Girl Genius has an artistic style that perfectly matches the thematic content, which is... Hmm. I'd tell you what it's about, but I won't because I don't want to give anything away, it's all too awesome for me to risk messing it up. Suffice it to say that it's relentlessly silly, (though with some serious themes about identity) manically detailed, and there's always a reasonable likelyhood that someone will throw a bomb at you.