refrigerator
Explanation
The Joke
The comic takes the classic prank call setup -- "Is your refrigerator running?" -- which traditionally leads to the punchline "Well, you'd better go catch it!" Instead, the person on the receiving end answers "No..." and the caller responds with "Then I hope you have dry rations!" The caption reads: "Prank calls became more somber after The Apocalypse."
In a post-apocalyptic world, a non-running refrigerator is not a setup for a silly joke but a genuine survival concern. If your refrigerator is not working (presumably because the power grid has collapsed), your food will spoil, and you will need to rely on dry rations that do not require refrigeration.
The Humor
The comedy comes from applying the structure of a familiar, harmless prank call to a grim post-apocalyptic scenario where the joke's premise becomes a real and serious problem. The format of the prank call is preserved perfectly -- the question, the pause, the response -- but the content has shifted from silly wordplay to genuine concern about survival. It is a classic SMBC move: taking a well-known cultural format and transplanting it into an absurd context where it becomes darkly funny. The word "somber" in the caption perfectly captures the tonal shift, as if prank callers in the apocalypse still feel compelled to make calls but can only manage bleak practical advice.