I was unable to find an image of this, but I remember that Plessey Semiconductors made a long "bucket brigade" analog shift register (I think it was for LeCroy?) that had to be bent into a Z shape to fit on the chip.
The chip designer had room inside the Z, which looked something like a railroad, so he copied a steam locomotive from his child's coloring book and put it on the substrate.
(Tektronix draftsmen often did the same thing with their schematics, such as a skier going down a diagonal line on a flip-flop circuit.)