"Cow tools" is a cartoon from The Far Side by American cartoonist Gary Larson, published in October 1982.
In response to the controversy, Larson issued a press release clarifying that the thrust of the cartoon was simply that, if a cow were to make tools, they would "lack something in sophistication".
[5][6] Larson took the unusual step of issuing a press release, explaining the joke: The cartoon was intended to be an exercise in silliness.
I regret that my fondness for cows, combined with an overactive imagination, may have carried me beyond what is comprehensible to the average Far Side reader.
[1]Years later, in The Prehistory of the Far Side, Larson further explained that he was inspired by the idea that tool use was the characteristic that separated humankind from the rest of the animal kingdom.