FREE: thank you drawing***please read***

There's no telling whether you'll get a lot of credits or not. I've seen really good artists get very low bids, and bad or mediocre ones get surprisingly high ones. It all depends on the bidder's taste (or lack of taste) and fleeting whims. I got 1,030 credits for one art auction, but only 1 credit for most of my others. But the right bidder has to happen by while your auction is up, too, so it may help to keep the auction up longer.
For best results, I recommend that you put up a few different kinds of pictures and see what ones people go for. You may even want to re-auction any successful images. But don't put up multiple auctions of the same image simultaneously, because that can be annoying. Lastly, if you're feeling adventurous, you might try an auction with the offer to draw whatever the winner wants. Just be sure to be clear about your exceptions (e.g., offensive subjects, or certain things you feel you just aren't good at drawing). And it's helpful to give details in your description: I liked that this auction gave a lot of information for potential bidders.
Not having a minimum bid can be good, too; even if you don't get a lot of points, you get a better indication as to how many people are interested.
Although I personally don't have much use for what you're auctioning here, I think it looks very nice, and I hope your auctions do well!