Judo Kittens stickers.
Judo Kittens are a popular group of presumable superheroes. They were particularly favored by Muffy and Francine. Muffy owned a page of Judo Kitten stickers, which she promised to give to Francine. During the Desk War Muffy stuck the Judo Kittens Stickers on Brain's desk after George didn't give her Brain's pencil after sharpining it. They are seen in Desk Wars.
Trivia
- Judo Kittens somewhat resemble the Powerpuff Girls, a popular cartoon superhero group.