From "The Pre-History of the Far Side":
"The 'Cow tools' episode is one that will probably haunt me for the rest of my life. A week after it was published back in 1982, I wanted to crawl into a hole somewhere and die
'Cows, as some Far Side readers know, are a favorite subject of mine. I've always found them to be the quintessentially absurd animal for situations even more absurd. Even the name 'cow,' to me, is intrinsically funny.
"And so one day I started thinking back on an anthropology course I had in college and how we learned that man used to be defined as 'the only animal that made and shaped tools.' Unfortunately, researchers discovered that certain primates and even some bird species did the same thing -- so the definition had to be extended somewhat to avoid awkward situations such as someone hiring a crew of chimpanzees to remodel their kitchen.
"Inevitably, I began thinking about cows, and what if they, too were discovered as toolmakers. What would they make? Primitive tools are always, well, primitive-looking -- appearing rather nondescript to the lay person. So, it seemed to me, whatever a COW would make would have to be even a couple notches further down the 'skill-o-meter.'
"I imagined, and subsequently drew, a cow standing next to her workbench, proudly displaying her handiwork (hoofiwork?). The 'cow tools' were supposed to be just meaningless artifacts -- only the cow or cowthropologist is supposed to know what they're used for