milk
Explanation
The Joke
A farmer is confronted by someone who asks what he is doing to a cow. The farmer explains that he is squeezing the cow's nipples to "take your milk." When asked "what?!", he elaborates on his bizarre plan: he is going to inoculate the milk with bacteria, let it sit until it becomes a solid block, then sell it to rich yuppies. The final panel shows the cow looking disturbed as the farmer continues squeezing, with the scene framed to emphasize how strange this all sounds from the cow's perspective.
The comic takes the completely ordinary and ancient process of milking a cow and making cheese, and re-describes it from scratch as though it were a bizarre, disgusting new idea being pitched for the first time. When you strip away thousands of years of cultural familiarity, the process of extracting bovine mammary secretions and letting them ferment into solid blocks does sound quite unhinged.
The Humor
The humor is a classic defamiliarization gag. Cheese-making is one of humanity's oldest food traditions, but when described in blunt, literal terms -- squeezing nipples, inoculating with bacteria, selling solidified results to affluent consumers -- it sounds like the ramblings of a madman. The cow's horrified reaction serves as the audience surrogate, reacting the way any rational being would if they heard this plan for the first time without cultural context. The mention of "rich yuppies" adds an extra layer, poking fun at the artisanal cheese market where people pay premium prices for what is, at its core, carefully controlled milk rot.