honey
Explanation
The Joke
Two prehistoric-looking men are shown. One is tasting something and exclaims that it is the most delicious substance in the universe. The other explains that it is called honey. When the first man asks where it comes from, the second answers: "Only from hives of venomous insects who live in massive swarms."
The red-button bonus panel delivers the punchline: "Thog is generally considered the first atheist." The implication is that upon learning that the most delicious food on Earth can only be obtained by raiding colonies of stinging insects, Thog concluded that no benevolent God could have designed such a system. If a loving creator existed, surely they would not have put the best-tasting substance behind a wall of angry, venomous bees.
The Humor
The joke works by reframing something we take for granted -- honey -- through the eyes of someone encountering it for the first time. When you think about it from scratch, the fact that the tastiest natural sweetener is produced exclusively by swarming, stinging insects is a genuinely bizarre arrangement. The comic uses this observation as a comedic argument against intelligent design: the apparent cruelty or absurdity of making honey only accessible through pain and danger is presented as evidence against a benevolent creator.
The punchline connecting this to atheism is the comedic payoff. It is a humorous take on the Problem of Evil (or in this case, the Problem of Inconvenient Deliciousness), reducing millennia of theological debate to one caveman's frustration at getting stung while trying to eat something tasty.
References
The comic plays on the Problem of Evil and arguments from design in the philosophy of religion. The idea that the natural world's apparent flaws or cruel arrangements undermine the case for a benevolent creator has been a staple of atheist argumentation since at least Epicurus. Honey bees (Apis mellifera) are indeed venomous -- their stingers inject apitoxin -- and they live in colonies of tens of thousands. Humans have been harvesting honey for at least 8,000 years, as evidenced by cave paintings in Spain.