Apple made a commercial showing tons of different decals made to go on the back of a MacBook, often incorporating the Apple into the design.
https://www.youtube.com/watch?v=7PzntWQ-sVY
A celebration of all the many ways people love the MacBook Air, featuring music from artist/producer, Hudson Mohawke.
You can view the stills at www.apple.com/macbook-air/stickers/ which feature pop culture icons like Cookie Monster, Homer Simpson, Space Invaders, Breaking Bad, and many more.
If you would like to buy a decal for your laptop, Amazon has a whole category devoted to laptop skins and decals.