Oo, a goth one. Any particular design like a goth cross or skull and cross-bones?
Typically, I search on Google Images for a certain subject and then for the dimensions I put down "100 X 100" so I get the right size image. Then I just click on the image, click "View full image" on the side screen, and then copy the image URL. I found my Ciel Phantomhive avatar that way.