As you know, engineers tend to have a unique sense of humor. And the folks who design computer chips are no different.
“The Silicon Zoo” is a collection of animals and other artworks that are etched into the circuitry of any number of chips.
The size of the artwork is generally measured in microns (millionths of a meter) and is thus much too small to see with the unaided eye. You can find everything from Daffy Duck on a RISC processor to Marvin the Martian on an image sensor used by Spirit and Opportunity.
You can even find Waldo!