From the PreHistory of the Far Side (p. 156):

The “cow tools” were supposed to be just meaningless artifacts—only the cow or a cowthropologist is supposed to know what they’re used for.

The first mistake I made was in thinking this was funny. The second was making one of the tools resemble a crude handsaw–which made already confused people decide that their only hope in understanding the cartoon meant deciphering what the other tools were as well. Of course, they didn’t have a chance in hell.