4-panel comic by War and Peas.
Panel 1: A group of cows gathers in what looks like a secret meeting room. A brown cow, standing at the head of the group, speaks: "It is once again time to discuss how to get rid of the human scum." Another cow asks, "Any ideas?"
Panel 2: One cow replies, "We could fart."
Panel 3: The cows collectively consider the plan, looking at a diagram showing a fart cloud eliminating humans.
Panel 4: A newspaper headline reads "METHANE DESTROYING ENVIRONMENT!" accompanied by an image of coffee and a plate of bacon, hinting at the cows' revenge.