Censorship Panda
From WikiFur, the furry encyclopedia.
The Censorship Pandas are a collection of images intended to represent site ratings. They range from Gee, the G rating, to Lady X, the NC-17 rating (plus Nyra for not-rated sites), and are provided for free by Amber Williams of Mab's Land. Williams has also been known to provide custom rating images for favorite webcomics, including Jack and Nivlek.
You can see the pandas at the Adopt a Censorship Panda page, or in WikiFur's rating images category.